1975 R75/6 Rebuild: Project Index

Contents

This bike is my first BMW purchased in August 1975. I did a rebuild in 2009-2010 and later, a “Freshen Up” in 2015-2016.  This is the first build I blogged about and I’ve learned more about how to improve my documentation and about how to rebuild and restore airheads since 2009. To date, I’ve rebuilt this bike, a 1973 R75/5, done a number of projects on a 1984 R100RS and also done a number of “freshen up” projects on this 1975 R75/6.

The Table of Contents (above) should help you go directly to any project of interest. The 2015-2016 Freshen Up projects are at the end of this page with links to the main subsystem the projects are associated with.

I hope this information is helpful to you.

DISCLAIMER

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Please be advised that there is no representation of the accuracy of any of the information presented on these web pages relative to BMW motorcycle maintenance or modification and that the material is presented for information purposes only. In no case will I be held liable for injury or damage (consequential or otherwise) resulting from or arising out of alterations you make to your motorcycle. The reader should recognize that motorcycling is a dangerous activity that can result in injury or death, and that the alterations portrayed on these web pages can and will change the behavior and performance of your motorcycle, possibly with fatal results. You are encouraged to seek qualified assistance before undertaking any of the procedures outlined here, and are here by notified that, should you decide to proceed, you do so at your own risk.

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Silver Ghost Restoration-Epilog, November 3, 2010.

Here’s a short video of the startup of the Silver Ghost on Halloween night.

And, you can look at a summary of before, during and after photos of the build here
and see the entire set of photos here.

The following consolidates the blog entries I’ve made on doing the build starting with this Epilog, an d then a choronology of the build.  I’m the original owner of the bike which so far has accumulated over 103,300 miles.  I hope this  material proves helpful to others who are interested in keeping an older BMW running or doing a rebuild.

Lessons Learned

Before I started, I read a blog that said “Start from the inside and work your way out.” .  The logic made sense to me in developing the budget.  I estimated the cost for the frame straightening and fork tube replacement I knew were required.  This was the most expensive work I had done, and ended up costing about 50% more than the estimate.

After that was done, I prioritized the other “must do” work. I had the top end inspected and got cost estimates for repairing the broken fin on one head.  The estimates ranged from over $100 to about $15.  I took the $15 bid from Randy Long even though shipping to Pennsylvania and back cost me $25.  When he got the head, we talked and he pointed out the valves, guides and seats were worn and past their service life.  So he got both heads and I had him replace the seats, valve guides, springs and valves.  Randy does great work and is willing to share his knowledge.

I priced out a carburetor repair of a broken float pin boss and the parts for rebuilding it. I replaced the rear sub-frame with a good used one since I knew it was cracked and been repaired and cracked again, and a new exhaust system as the original I had held on to was in bad shape.

I developed an estimating spreadsheet to forecast the costs and updated the total with actual cost when I bought parts.  Its a good idea to identify “must” from “nice” to have parts.  Get all the must have parts priced and paid for and then work on the nice to have sourcing new and used parts (eBay, BMW MOA forum, Craig’s List, Vintage BMW Motorcycle Owners group, and the BMW Internet Riders forum).

Optional parts included a used cast “snowflake” rear wheel to match the front one I bought in 1982, a used R90/S fairing, new Dyna III electronic ignition, used bar end mirrors, and used battery tray.  Checking the on-line used markets and eBay for about a month turned up deals on many of these parts, so I spent the money.  With eBay, I only had one part with some disappointment, the cast snowflake wheel which had a dig in the rim.  But, I found a local company, Woody’s Wheel Works, who could pound it out.

Painting was a shock as I originally planned to have it professionally painted.  But, after multiple bids over $2,000, I called a friend who rebuilds classic British bikes for some advice.  He talked me into the “growth experience” of painting the bike myself.  He had the equipment, advice and encouragement.  I had to do the rest.  It took me 3 times as long to complete the painting as I had estimated.  The material cost doubled when I had paint failures and had to buy another paint kit from Holt BMW.  But, the education and satisfaction were priceless.  It was the memorable experience of the project and even though I got very frustrated and discouraged more than once.  As my friend says, “Endeavor to Persevere”.  And, “There’s nothing about painting you can’t fix with sand paper and more paint.  You can’t break anything.”

CAUTION:
That said, ALWAYS get the primer that goes with your paint assuming you are using a multi-component paint system and not just “rattle can” painting the bike. The primer has to be happy with the solvent used in the base coat. NEVER use rattle can primer with auto quality paint, like I did, or you will get paint peeling. 

WARNING:
If you use professional two-part primer and clear coat, you are going to be exposed to chemicals that can permanently damage your lungs, brain and eyes. The damage is cumulative and irreversible. I did the paint work on three bikes (this one twice and the R75/5 project) using a lower face mask with filter. I will NOT paint that way again. If I ever paint with two-part paint systems again, I will have a full body suit and full respirator mask with separate oxygen source and complete skin coverage. ANYTHING LESS IS ASKING FOR PERMANENT DAMAGE. As I get older, I occasionally get wiser 😉

My original budget was more than the blue book value of the bike, and that is typical for a rebuild, or in my case, a build of an R90S cafe racer replica.  I kept detailed records of all costs.  The paint preparation (primer, sand paper), solvents, cleaners, shop supplies cost much more than I had estimated.  Don’t over look that in your budget.  In the future, I’d put in a 5% shop supplies budget and estimate primer cost at 30% of the paint cost.  The final cost exceeded the budget by 60%.  Plan accordingly.

Finally, there is practical value in figuring out how to overcome the “cussedness of inanimate objects”, not at the time, of course, but in retrospect  :-).   I’m reminded of Rober Pirseg’s book, Zen and the Art of Motorcycle Maintenance, “The real motorcycle you are working on is yourself”.  If that is true doing routine maintenance, then doing a rebuild of a bike means you are rebuilding yourself.

Resources

The web is a great resource for advice, parts, options and ideas.  I found a large amount of information, resources and “How To” advice for rebuilding bikes in general and BMW in particular.  I  asked questions on various forums and always seemed to find someone who had the tid bit I was looking for.  The available knowledge and willingness of folks to share what they know make taking on a project of this scale doable.  All you have to do is search and ask, and you can learn just about anything you don’t know.  I compiled a list of resources I found here.

I found Max BMW’s on-line parts fiche a reliable tool for cost estimating as well as other on-line suppliers of parts for classic BMWs (Benchmark, Rephyche, and Hucky’s).  My local dealer, BMW of Denver met or beat most of those prices but I did some business with internet sellers as well.

In particular, Clem Cykowski at BMW of Denver, Kent at Holt BMW and the kind folks at The Bing Agency were particularly helpful and supportive.  And of course, my friend Brian House, who encouraged me to learn how to paint motorcycles and lent me his equipment was a great resource of tips, advice and wisdom.

Tips for Those Who Follow After Me

In no particular order, here is my list of tips when doing a project like this.

  • You can do this work with simple tools in your own garage.
  • Clean out a work area and keep it clean
  • Newspaper is a your friend.  Keep it handy, cover your work bench with it, change it often.
  • Shop towels on the roll are very handy.  Buy a half-dozen rolls.  They are always “clean” when you need them.
  • Take pictures as you take things apart.  You will not remember how everything goes together in a year.
  • Bag parts as you remove them in plastic zip lock bags and label them with what they are (front fender, shocks, etc.)
  • Use boxes to hold parts bags for major subsystems.  I put all electrical parts in a box, all engine parts in a box, etc.
  • Keep a list of “to buy” parts as you remove them.
  • Assume you will buy all new rubber parts.
  • Develop a “to do” list for work you have to do and think about the best sequence to do it in.  You will save a lot time in end and avoid “redos”.
  • Monitor your patience, attitude and energy level.  When you aren’t feeling focused, confident, or happy, stop working.  You’ll just screw something up, usually something expensive or hard to find.
  • There is no rush.  Take your time and the stress goes away.
  • The fun comes from doing, thinking, planning and overcoming the “Oh Shit” that is inevitable.  Relax, have a beer, tomorrow’s another day.  If you aren’t in the mood, the bike is not going to go anywhere.
  • When you get stuck and don’t know how to get a part on, or figure out how to fix a mistake, clean the work bench.  You can control that, and in the process, solutions will come to mind if you will just be quiet enough to let them suggest themselves.

Painting

  • Sand paper and its proper use are critical to a nice paint job.
  • Preparation will take 80% of the time for painting.
  • Sand the last coat with a finer paper than the previous coat.  For 3 coats of primer, 320 grit, 400 grit, 600 grit.
  • If you are painting base coats with silver or black, add a fourth coat of primer and sand at 1500 grit.
  • Clear coat looks very shiny when it goes on, but it has to be sanded to remove the “orange peel” and dust motes.  Use no coarser grit than 2000 and finish with 2500 grit.  Then you can buff it out with scratch remover.
  • You can’t really ruin anything when painting.  If you make a mistake, grab the sandpaper and erase it.  Worse case, paint it again.

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Silver Ghost Restoration – Part 1 Getting Started, Oct 26, 2009

My first BMW, a 1975 R75/6, was purchased for cash 34 years ago in 1975 at BMW of Denver from the then owner, Clem Cykowski.

The Grey Ghost - Starting a Restoration

The Silver Ghost – Starting a Restoration

I’ve ridden this bike 103,000 miles so far and in 2005, I received a BWW 100,000 mile award. Although you can get the award riding multiple bikes, it was my goal from the day I bought the bike to ride it 100,000 miles. In the 34 years since I bought it, I’ve had many adventures and two minor accidents.

Brook (on the right) Getting BMW 100,000 Mile Award in 2005

I raced it for a season (accident #1 was in my first race, but I still finished 2nd). It has a few engine modifications including titanium push rods [I bent the original push rods in the 1st race. I acquired a lot of “wisdom” that day 🙂 ], a lightened fly wheel and a drilled air cleaner case to let it the engine breath a little easier.

In 1984, I took a month off for mental health reasons (the job was way too stressful) and spent most of that month in my garage doing a “freshen up”. The original paint was cracking and I wanted to upgrade the supsension, exhaust and put a new Windjammer V faring on it. I loved the R90-S Smoke Silver paint scheme and had it repainted Smoke Silver (or at least a decent approximation). I took off the stock exhaust and mufflers and added a Luftmiester black chrome two into one exhaust with a little “throat” to it (aka, louder). I put on a “snow flake” cast front rim, braided steel brake line, /7 series black valve covers and spot painted the dings in the frame. I also replaced the handle bars which had a tweak from accident #1. The opportunity to just work at my own pace and think things through when I needed to without any time pressures was very relaxing. At the end of the month, both the Silver Ghost and I were refreshed.

Several years later in the late 1980’s, I didn’t stop quick enough in traffic (accident #2) and rear ended the car in front of me. I wasn’t hurt and the car couldn’t have cared less, but I did shorten up the wheel base a tad. The bad news was the steering head was bent and likely the fork tubes as well. The good news was the bike was even more nimble with quicker steering in the corners and until now, I just let it go.

“So, why restore it?”, I’ve been asked. I don’t have a logical answer. It just feels like the right thing to do. It’s a machine that has been in my garage or under my butt a large part of my life. I’ve learned a lot about motorcycles, and some about myself since I’ve owned it. Not to anthropomorphize about this, but “the Silver Ghost” is a good friend of mine and investing in a restoration seems like a logical next step in our relationship.

Recently, I’ve been reading books and blogs about reconnecting the mind with the body and the brain research that demonstrates the intimate link between “hands-on” tinkering. brain plasticity and a sense of well being. Okay, I haven’t done much hands on for quite awhile. It’s time to do some tinkering and see how much plasticity this brain has left.

Clem, is still working on BMW’s and is still part of BMW of Denver. He sold the company several years ago, but is working in the shop on the classic and vintage machines as “Heritage Model Specialist”. I’ve talked to him about the bike and had him look it over. We have a plan of attack.

Step one is to get the frame straightened and the fork tubes checked, and likely replaced. This Sunday, I went to Home Depot and bought an electric space heater so I would be a bit warmer in the garage since winter was making a visit with cold temperatures and snow flurries outside. I spent some time taking off the Windjammer IV fairing, front fender and rear luggage rack. I took some before pictures. This coming Saturday, Holloween, I’ll take it over to Clem to pull the fork tubes to see if they can be straightened, get the steering head and frame straightened, and install new steering head bearings, new fork tube seals and the new fork gaiters I bought.

In the meantime, I’ve been pricing parts, looking at other restorations for ideas, and dithering about trying to paint it myself or, like the last time, pay a professional paint shop to repaint it.

My youngest son, Branden, is interested in helping out and getting his hands dirty. I’m looking forward to the company and the opportunity to share what knowledge I have and learning what I don’t know, which is considerable I’m sure.

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Silver Ghost Restoration-Part 2, Front End & Frame

Saturday, I rode the Silver Ghost to BMW of Denver to get the steering head and frame straightened and the fork tubes inspected. I’m pretty sure the tubes will get replaced. As I noted in the previous post, I had stripped the bike of the fairing, front fender and rear luggage rack.

The ride down caught my fancy and here is a write up. I hadn’t ridden the Ghost without the faring in a long time. I’ll look to get the Ghost back at the end of November.

Here’s the view in the driveway before we left.

“Naked”

103,000, one owner miles

103,322 Original Owner Miles

What My Friend Pete Sees a Lot Of :-)

Rear – Clean Shaven

Money Shot.

Dog’s Eye View

Luftmeister Exahust Crack

Crack repair in Luftmeister 2-into-1 pipe … Stock pipes going back on.

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Silver Ghost Restoration-Part 3 Engine

First, a quick update on the frame straightening. I got the Ghost back in December after dropping it off on Halloween. I was in South Africa most of November. As the fork tubes were bent and on back order, it took a few more weeks to get them and complete the front end work. Replaced parts included the upper and lower triple clamps, but fortunately, I secured a used lower clamp at $250 which was a good savings over the $460 retail.

Today, my youngest son, Branden, came over and he took apart the the top end with some instructions from me. I’ll take the parts over to BMW of Denver so Clem can check them out. I suspect the valve seats will need replacing and the valves lapped. I’ll also install new ring sets.

Here’s the sequence of steps Branden followed to take apart the top end.

Remove Carbs & Plugs

This is pretty straight forward. Removing the cables and the air tubes securing the carbs is simple. Remove the air tubes then detach the throttle and choke cables from the body. Branden is holding the carberator showing where the throttle and choke cables attach to on the back side of the carberator.

Carb removed

When Branden pulled the plugs, it was clear the right side (top plug in the picture) was running pretty lean. We’ll be doing a carb rebuild and will balance the carbs when we reassemble the bike. I tagged the plugs with the side they came from so I can keep track of things like this.

Plugs - Top is Right, too lean

As Branden removed parts, we put the parts we are keeping in the garage in one box, and the parts to take to BMW of Denver in a second box. It’s good to label parts for which side they were on and take pictures during disassembly. You don’t know how long it will be before you put things back together and you will forget small details. Labels and pictures save a lot of time and mistakes.

Parts box

Here’s the bike when Branden got the carbs and plumbing removed.

Carberator and pipes removed

Remove Exhaust

We used the BMW supplied wrench to remove the exhaust nuts securing the headers to the heads. Since these nuts are cast aluminum, banging on them with a mallet is a great way to break them. The wrench ensures this won’t happen. Be careful fitting it to the nut and make sure its inserted all the way or you can break a fin on the nut. You can use a cheater tube on the end of the wrench to get them loose, or you can use a mallet on the wrench handle to get the nuts to loosen up. Then, you can spin them off by hand. Branden used the mallet.

Exhaust pipe nut wrench

Next Branden removed the bolts securing the muffler to the right exhaust hanger. I had installed an after market Lueftmeister 2 into 1 exhaust back in 1980. You have to remove the pipes from the right and left hangers if you have the standard exhaust. I’ll be installing the stock muffler and exhaust pipes on this rebuild. The Lueftmeister has a crack. so I’ll like scrape it or sell the headers on Ebay.

Bolts securing exhast

There are steel rings inside the exhaust nut that seal the exhaust pipe to the head. These nest into each other to create a seal preventing exhaust gas from blowing by the exhaust pipe. The outer ring is solid with a square profile and curved inside radius. The other ring is split and has a beveled profile. These fit together as shown. I taped them together the way they are assembled so we won’t have to think about how they go together when we reassemble the exhaust.

Exhaust head nut and seal reing

Exhaust pipe seal rings

Here’s the bike with carberator and exhaust plumbing removed. We found we had to also remove the rear brake peddle to allow Branden to remove the exhaust.

Exhaust off the bike

Remove Valve Covers

There is a chrome nut in the center of the cover and also two small nuts behind the valve cover near the intake and exhaust pipes. You can see the stud on the cover here.

Back side of valve cover-stud w/ nut

It’s a good idea to put a pan under the cover as oil will drip out from the bottom of the valve covers when they are removed. You can see the oil stream as Branden pulls the cover off.

Pulling valve cover loose

Remove Cylinder Heads

The cylinder studs extend through the head and are used to secure the rocker arm assemble of the valve train. These are torqued in a cross-wise pattern, so I like to loosen them in a cross-wise pattern and then remove them.

Removing rocker arm nuts - cross pattern

Removing rocker arm nuts - cross pattern

The rocker arm assembly has two square steel blocks, pillow blocks, on top and bottom of the rocker arm assembly. There is also a shaft that the rocker arm rotates on. Inside the rocker arm are needle bearings. Branden has his thumb on the rocker arm. The pillow blocks are visible with the slot cut through one side and the shaft the rocker arm rotates on can be seen at the center of the pillow blocks. The nuts on the cylinder head studs have been loosened.

Rocker nuts loosened

To avoid dropping various parts, its a good idea to pinch the pillow blocks as you slide the rocker assemble off the cylinder head studs. Branden is squeezing the pillow blocks together as he slides it off the cylinder studs.

Pulling rocker arm assembly off

Next Branden pulled the push rod out and labeled the parts showing the side, and if the rocker was the intake or the exhaust so we can assemble them correctly. Note that my push rods are not the standard steel ones. They are titanium racing rods. See Part 1 about how those got there 🙂

Rocker arm with pillow blocks & Push Rod

Branden then removed the nut that is above the spark plug hole. There is a second one on the bottom of the cylinder head directly beneath the top one. Although I haven’t dropped one into the spark plug hole, be cautious when removing it. If you do drop it inside the engine, no worries because in another minute, the heads come off anyway so you can retrieve the nut.

Top nut securing head

It’s time to remove the heads. There is a head gasket and sometimes the head does not want to slide back right away. Working it back and forth will loosen it enough for it to slide back. Be careful you don’t pull too hard, or when it comes loose, you can end up on your butt or drop the head. Be patient. It took Branden a couple of wiggles to get it loose.

Pull head off

Remove Cylinders

I like to position the pistons at top dead center before removing the cylinders. This leaves the connecting rod extended as you pull the cylinder back. I don’t want the rod to fall onto the engine case when the piston comes out of the cylinder, so once enough of the connecting rod is exposed, I stuff some shop rags between the connecting rod and the engine housing to support it. The base gasket can also be a bit stubborn, so you may have to rock the cylinder a bit to break it loose. Branden didn’t have that problem on either cylinder.

Head off, piston fully extented

Rags supporting connecting rod

Gently pull the cylinder back and catch the piston with one hand and gently let it rest on the cylinder studs. It is a good idea to wrap it in some shop rags so you don’t harm the rings. We’re going to replace them, so we didn’t worry about that.

Head off some cross hatching still visible

Once the cylinder is off, you can remove the head gasket.

Head gasket & piston

And you can remove the push rod tube boots. I knew they were leaking, so likely they were split. As you can see, that’s the case.

Push-rod tube seals - cracked

Remove Pistons

To remove the pistons, there is a C-clip on each side of the wrist pin that has to be removed. There is a slot at the top of the wrist pin hole in the piston. Use an awl in the slot to pry the C-clip loose.

C-clip removed - note recess

Branden is using the awl to pry one of the C-clips loose.

Awl in recess removing C-clip

Now, we have to remove the wrist pin. You need a drift to help tap the pin out. I use an appropriate sized socket with an extension as the drift. Be careful that the diameter isn’t too large or too small. The socket should rest on the shoulder of the wrist pin. Use a rubber/plastic mallet and tap gently increasing the force a bit until the pin starts to slide out the other side. The mallet ensures you don’t ding the piston or rings should you miss hitting the drift.

Using drift to remove wrist pin

Wrist pin coming out

We labeled the pistons and wrist pins so we know which is from the right and left cylinders. Here’s a picture of the pistons, wrist pins and tools used to remove the wrist pin.

Pistons, wrist pins, tools

We completed the top end disassembly in about 2 and 1/2 hours working at a leisurely pace.

Here’s the heads and cylinders after removal.

Cylinder and head removed

Cylinder and head removed

Next week, I’ll take the box of top end parts to Clem at BMW of Denver to inspect them and we’ll see what needs to be worked on or replaced. In the meantime, I’ll be looking for more parts on eBay, inspecting the stock exhaust that I had stashed back in 1980 when I put the Luftmeister 2 into 1 on to see if I need to replace some of the components. I also am on the hunt for a good local motorcycle paint shop. I’ve finalized the color to be R90/S smoke silver similar to what is on the Ghost now. However, that paint job was not done correctly, so I’ll be looking to get this one right.

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Silver Ghost Restoration-Part 4 Getting Ready for Paint Shop

I’ve bumped into a fellow, Dave Porter, in town who owns a bycycle shop (Aravada Bycycle Company) and who also has a business selling used, new and NOS Triumph parts and does Triumph restorations. It turns out, his son and my son have been friends throughout their school years.

Dave gave me a couple of leads on folks in the Denver area (one in Arvada) who do paint work. Today, I pulled the rear fender, side covers and tank off the Silver Ghost in preparation for getting some painting estimates.

The first step was to remove the tail light bracket & turn signal bracket along with the license plate holder

Tail Light Bracket Remove

Next, I removed the four bolts that attach the fender to the subframe and carefully rotated the fender toward the rear around the tire. I kept all the bolts and steel straps on the rear subframe so I don’t loose them. I’ll be removing the subframe and replacing with a used one since the original subframe has cracked and broken through.

Rear Fender

Last, I removed the gas tank and drained the fuel into a gas can. Remember that each pet cock has a reserve setting, so you have to drain the reserve fuel from each side. Then, with all the gas out, remove the pet cocks from the tank. The nut next to the tank takes a 24mm open end and pet cock body takes a 17 mm open end.

Here’s the end result. Total time was about 45 mins.

Rear Fender Removed

Fenders & Tank off

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Silver Ghost Restoration-Part 5 Battery, Ignition, Exhaust, Carbs, Misc Parts

I’ve been busy using Max BMW’s parts finder to look up parts and retail prices. I put together a spreadsheet to collect all that information and to let me do some “what if” scenarios on options. I’ve also been visiting eBay regularly for their motorcycle parts listings. It’s amazing what and how much for old BMW’s is there. It’s a great resource.

Battery Box

I’ve decided to replace the modified battery box that I cut the sides off to fit a lawn tractor battery, with a stock box. eBay has quite a few of them as good prices.

Battery Box

Instrument Cluster

The instrument cluster has a cracked back where the cable harness plugs in. I also suspect the circuit board wiring has a break as some of the lights don’t illuminate. I found this set on eBay. The exterior plastic housing is pretty scratehed, but he parts I really want are in good shape.

Instrument Cluster Parts

Exhaust System

I had kept the original header pipes and mufflers with the intent of using them again. But upon finding them and looking at them, they are dented, scuffed and pretty used up. So, new exhaust and mufflers from an after market supplier (stock BMW is just too $$$$)

Niche Supply – R75-6 Complete Exhaust System

Ignition System

The points ingnition system needs to be upgraded. The breaker plate has problems and I’m not sure the points cam doesn’t need to be replaced. I had the heads bored for dual plugs and used an Accel amplifier and dual ignition coil set back in 1980, but it was diagnosed as faulty several years ago. I pulled the second plug wires, bought new coils and went back to the stock ignition. Okay, let’s do the DynaTeck electronic ignition with dual port coils and a new set of dual plug wires in YELLLLLOOOOWWWW ….

Dyanteck D35-1 Electronic Ignition

DyanTeck DC2-1 Dual Port Coils

YELLLOOWW Dual Ignition Wires

Carburetors

I broke the float hinge post on one of my carbs many years ago. I had epoxed it together, but that really wasn’t working. Several years ago, to get on top rough running problems, I found a carb body from an R75/5 and used that. I still have the orignal carb body. You can see the left pin is shorter than the right.

Bing Carb - Broken Float Hinge Casting

The Bing Agency offers parts and repairs for all Bing carbs used on BMW motorcycles since 1926. They can fix this broken pin. It’s about $35.00, so I’m going to send it to them and let them do their magic. I wish I had known about them back when I decided to buy the used R75/5 carb body. No worries. Either I’ll put it on eBay or use it when I rebuild Rochelle’s R75/5. I’ve been looking at their rebuild kits, and am going to go with the #6 kit. That provides all new gaskets, o-rings, diaphrams, jet needles, needle jets, float needles, new floats and the throttle plate screws. As my carbs are 35 years old w/ 100,000+ miles, I think they deserve a complete rebuild.

Mirrors

I also stumbled on some R90-S bar end mirrors the other day, and decided to go with them. I’m either going to restore this as a naked bike, or budget permitting, put an R90-S style bullet faring with screen on the front.

R90-S Bar End MirrorsR90-S Faring

Font Turn Signals

I lost the front turn signal stalks when I put the Windjammer on. I picked up front stalks, turn signals and lens on eBay. Shortly thereafter, as I was cleaning up the garage and going through my various part stashes, I found my orignal signals and lens. Eventually, something will go back on eBay.

R75-6 Front Signal stalk, signals, lens

R90S Style Faring

I’d like to put this on the bike as it has a cool 1970 cafe racer style to it. Budget is the issue.

R90-S Faring

I found that Boxer Cafe has some reproduction R90-S faring with dash at a very good price. They advertize windscreens from Gustafson that are pretty inexpensive as well. When I get the paint estimate, I’ll decide what I can afford.So, most of the parts are identified and many ordered from suppliers. Clem hopes to complete checking out the top end of the engine by the end of next week.

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Silver Ghost Restoration-Part 6 Paint Schemes

I’ve been looking on-line for pictures of cafe-racer restorations, typically those for BMW models. When I started, I thought I would follow an R90-S style. Here are some pictures of what I had in mind.

Here are some very nice cafe racer models I found.

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Silver Ghost Restoration-Part 7 You Want HOW MUCH !!!

I’ve been scoping out the painting and have a couple estimates from shops who do motorcycle painting. I’ve also been combing the web for information on painting, preparation and do it yourself painting.

I’m debating if I want to add an R90S bullet faring and also if I want to add a new cafe racer style seat with tail cone. Part of that decision is controlled by the budget. Adding these parts includes adding the cost of painting as well.

R90S Bullet Faring

R90S Seat w/ Tail Cone

I talked with a local shop about my ideas for the paint scheme and spent some time discussing how to prepare the parts prior to painting as I’m certainly able to strip and sand with the best of them 🙂 I also provided a description of the paint project to a nationally well respected motorcycle restoration painting company to see what they would estimate.

My reaction after I got the estimates: YOU’VE GOT TO BE KIDDING !!!! Nope, they aren’t.

When I had the Silver Ghost painted in 1981 in an approximation to the R90S Smoked Silver paint scheme, I think it cost me less the $500 to have have the tank, fenders and side covers stripped, painted and hand pin stripped. It’s north of $1,000 for that if I do all the paint stripping and also sand the primer and color coats at the local shop. Adding the tail cone and fairing pushes their estimates north of $2,000. The nationally respected paint shop is also north of $2000 if I provide stripped parts ready to prime and paint 🙁

That’s a budget buster.

It turns out I have an acquaintance who restores Trimuph motorcycles and cars and is a professional gear head as well as machinest, Brian House. I figured I’d call him up and see what he could suggest for options. Well, one thing lead to another pretty quickly. He does his own painting, has the compressor and guns and offered to show me how “to do it yourself”. That’s cool because I’ve had a hankering to try my hand at painting, but didn’t feel qualified nor did I have access to guns, compressors, etc.

This afternoon I brought the parts over to his place so we could talk about the process. In the meantime, he showed me the 1968 Ford pickup he is restoring and some pictures of two of his Triumph restorations. Drool … very nice.

We are going to paint with laquer as its a “forgiving” media compared to the currently popular urethane two part paint systems a lot of the shops use today. Based on the pictures of the Triumph he restored, the laquer work he produced was awesome.

The conclusion from inspecting the parts is I need to strip the tank to bare metal as the almost 30 years I got out of the last paint job has resulted in paint cracking down to the primer. We will hand sand the fiber glass parts down to the gel coat and fix the cracks at the bolt holes with fiber glass resin and cloth for strength.

Stay tuned for the adventures of Brook and Branden as we learn our way around “DIY” motorcycle painting. I’ll be providing detailed descriptions of the preparation and painting process as we work away under Brian’s tutlege.

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Silver Ghost Restoration-Part 8 Update on Parts, Engine & Work Plan

Parts have been coming in and I’m under the impression that I’ve ordered most of what I need. To date, I’ve received:

  • Battery Box, strap and hardware
  • Bar end mirrors
  • Electronic ignition and 2-port coils
  • Ignition wires
  • Exhaust and mufflers
  • Instrument cluster circuit board and back plate

I sent one of the carburetors to Bing International last week. See part 5. I ordered the #6 rebuild kit and Bing Carburetor maunal which I’ll receive when they return the repaired carb.

Other items I still have to get include:

  • Clutch neutral switch and gaskets (leaking and bike doesn’t start in gear when the clutch is pulled in)
  • Gas tank rondels
  • Gas tank nuts and washers
  • Cylinder head gasket (seems I only have one, not two)
  • Rings

I also have to decide if I am going to keep the stock seat, or get the Bushong cafe seat w/ tail cone and have that upolstered and paint it . And, I have to make the call on the R90s aftermarket fairing.

I heard back from Clem at BMW of Denver last week on the engine. The good news is it checked out fine. I was concerned the valve seats may have needed replacement, but they are doing well. I’ll need new rings, but that’s about it for engine parts as I have all the gaskets except one.

One of fins on the right cylinder head got broken [I hooked my car bumper on it a couple years ago when I was backing out of the garge … one of the lowest days I’ve had in a long time 🙁 I found a guy in Kansas, Cycle Works, that repairs them, and sent a note for a quote.

I realized that there are quite a few rennovations being done. I put together a spreadsheet of the work and then grouped the tasks by major subsystem. Finally, I organized them into a work flow that I hope will keep the work orderly and prevent forgeting tasks or having to remove what I just installed to do the next step. I was surprised by how many things are getting done. The task list will come in handy to help Branden and I coordinated.

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Silver Ghost Restoration-Part 9 Update on Carbs, Engine and Painting

Parts Cleaning

Well, not as much progress as I would have liked, but progress nonetheless. The weather has not been very cooperative for working in the garage until today. So, I washed and cleaned the fenders, tank and side covers in preparation for sanding them down.

I’ve also been grinding out the cracks in the fiberglass around bolt holes in preparation for repairing these stress cracks.

Grinding out Fiber Glass Cracks

Today I also got the cylinders and cylinder heads back from Clem. He has the rings gapped, and provided a new carburetor top as mine had a cracked throttle cable bushing. I also expect the repaired carburetor back from the Bing Agency next week along with the carb rebuild kit.

I sent out the cylinder head with the cracked fin to Randy Long of Long’s Custom Services in Pennsylvania. He specializes in head work and can repair the cracked fins. You can see the blue paint from the wheel well of my Saturn where I hooked the cylinder head when I was backing out of the garage. When I get the repaired head back, I’ve got a couple of places who can bead blast the cylinders and heads and I’ll get them cleaned up.

Cylinder Head Fin Damage

I’ve decided to go ahead and add an R90S fairing and may have located one in good shape with most of the hardware. I picked up the correct turn signal stalks which are longer than the ones on the R75/6 on eBay last week. The longer R90S stalks are used for the lower mounting points for the fairing.

I’ve been updating the budget as I go and right now I’m just a bit over budget based on current purchases and estimates for the remaining parts and materials, so that’s good.

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Silver Ghost Restoration-Part 10 Paint Stripping & Preparation

The pace picked up as the weather improved. I focused on stripping the paint and getting the parts prepared for painting. Everything is plastic on the R75/6 except the gas tank which is steel. So, sandpaper is your friend 🙂

Folded Sandpaper for Detail Sanding

I found that sanding the short radius curved areas first prevented rounding off the profiles. I used wet/dry paper and wet sanded to help the paper last longer. I dipped the paper in water and cleaned out the paint accumlulation from the paper frequently so it continued to cut quickly. As soon as I could see a good deal of paint flakes in the water on the parts, I’d wipe it up with rags so the paper wasn’t resanding removed paint flacks.

Brian told me to use 2 strips of paper, folding them in half, then inserting them so the seams are opposite each other. For sanding flat surfaces, this gave me four sanding surfaces and I got two strong edges for sanding the grooves and tight radius contours. With the paper wet, having the rough side of the paper under myu palm helped keep my hand from sliding off the paper. Go slow in the tight radius areas and contours to keep the edges crisp and avoid rounding them off. In the tighest areas, I used a small flat blade screw driver to crack the paint off. The blade is thicker than the paint scraper so it doesn’t gouge or scratch the plastic.

Removing Paint Along Detail

Sanding Front Detail

I wet sanded using 220 grit to start. I stripped the clear coat, color coat and primer coats until I started to take off the next to last primer coat. Then, using 400 grit, I stripped the next to last primer coat. This left a smooth surface so hopefully I won’t have as much sanding to get the new primer coats smooth. We shall see.

I found a used R90S bullet fairing with mounting hardware and windscreen on eBay for a good price, so I picked this up and added it to the stack of parts to strip.

R90S Fairing Ready to Sand

R90S Fairing Sanded Ready to Paint

I saved the gas tank and subframe for last and used aircraft stripper to get the paint off. I found that process was less labor intensive than sanding. I found it took several applications of the stripper following each with a paint scrapper to get the loosened paint off. The color coats and top primer coats would bubble up, but the lower primer layers required use of a paint scraper to get them off as all the stripper would do was soften them, not lift them.

Paint Stripper Bubbling Up Paint

Stripped Sub Frame Ready To Paint

After the paint was removed, I took a dremel tool to grind out any cracks that had developed in the plastic parts. Then, I used fiberglass resin to fill in the ground out areas so they won’t crack again. Any cracks will grow cracking the pain. The other impact is they also will soak up the paint and develop blisters, so you need be sure you get all of them ground out and filled.

Dremel Tool Ground Out Cracks

Plastic Crack Filler Fibre Glass Resin Filling Cracks

After the resin had cured, I sanded the area where fibreglass resin had spread on the surface near the crack. Then I used spot putty to fill in low spots and to smooth out and level the fiberglass resin filler in the cracks.

You need to keep the putty layers thin. It usually hardens in about 30 mins. I lightly sanded with 400 grit to smooth it out and if I needed another layer, added it. This part of the prepartion is fussy work, but getting the surfaces smoothed out as much as you can goes a long way to having a high quality paint finish, so take your time.

Stripped Gas Tank & Spot Putty

Fenders Sanded w/ Spot Putty Ready to Paint

I had a small crack in the dashboard of the R90S fairing between the cutouts for the two instruments. Again, I used fiberglass resin on the back to fix the crack. I found the fairing had been painted over the top of the original paint, so there was a lot more sanding required. Along the seam at the bottom of the wind screen the paint build up was quite thick so I took it down to the plastic using the folded sandpaper sandwich.

I estimate it took me about 30 hours to do the preparation for two fenders, two side covers, a gas tank and the bullet fairing. Patience is a virtue when it comes to preparing parts for painting. By the way, your finger tips are very sensitive and good measuring tools to feel high and low spots. Use them to check your spot putty filled areas as you sand them. If you can’t feel the edge you have it feathered into the surrounding surface correctly.

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Silver Ghost Restoration-Part 11 Removing Subframe and Rear Drive

The Ghost has an oil leak from the transmission neutral switch and, the subframe is broken. So Branden and I removed the old subframe, shocks, swing arm and rear drive and the transmission. Well, he did the work and I watched 🙂

Removing the subframe is straight forward. We removed the rear tail light and turn signal assembly earlier when we removed the rear fender for paint preparation. To remove the subframe, we disconnected the wiring harness from the tail light assembly and pulled it forward out of the front hole in the subframe.

Pulling Taillight Wire out of Subframe

Pulling Tailight Wire out of Subframe

Then we removed the bolts connecting it to the frame, the swing arm and the shocks so we could take the subframe off. You can see the broken section of subframe tubing Branden is holding. I had it welded about 8 years ago, but it didn’t hold up. Hence, the used subframe I scored on eBay.

Broken Subframe

Lower Subframe Bolt

Detaching Subframe

Next we removed the battery and battery box. In getting the battery box out, one of the lower rubber isolation bolts had a nut that we couldn’t remove. It had corroded and rusted enough that it was in between a 10 mm and 9 mm wrench size. So, we had to drill it out from top side to remove it. It’s the one on the right.

Frozen Battery Bolt

At this point, I put a board under the front of the oil pan to help support the bike so it wouldn’t fall forward when we removed the rear drive, swing arm and transmission. Then Branden drained the gear oil from the transmission, drive shaft and the rear drive. He also removed the tachometer cable from rear of the transmission by loosening the bolt.

Before Tranmission Removal

There are four bolts that that attach the transmission to the engine. You can see one of them in the upper left in this picture. There is a nut on the upper right used to attach the right side air cleaner housing and then two more bolts on the bottom.

Top Transmission Bolt

On the bottom of the transmission is the clutch throw out rod. Remove the clutch cable and then pull the C-clip on the top of the pin that attaches the throw out rod to the transmission.

Next, we loosened the drive shaft rubber boot to expose the universal joint. It attaches to the transmission output shaft with four twelve sided bolts. You can see one of them in the picture. Use a box end wrench to take these bolts off. We found that sitting on the rear tire while pressing the rear brake kept the drive shaft from turning while Branden loosened the bolts on the universal joint.

Pulling Rubber Boot Exposing Universal Joint

Sitting on Tire to Keep Drive Shaft from Turning

Next, we pulled the swing arm nuts using a socket that had been turned down to fit inside the swing arm housing. Then we backed out the bearings the nut secured so we could slide the swing arm and rear drive off the frame.

Cut Down 27mm Socket

Pulling the Swing Arm Bearing

Swing Arm and Rear Drive Removed

Rear End Removed

After that, we slide the transmission to the back and off the spline on the rear of the engine. When it cleared the engine output shaft, we pull it out on the left side. It wasn’t too heavy, but both of us supported it as we witdrew it so we didn’t score the splines or put let the transmisson hang on them.

You can see the old transmission neutral switch on the bottom of the transmission (I turned the transmission upside down, so the switch is on the top in this picture) just above the shift lever. The phenolic securing the switch to the nut had separated and I could spin the center of the switch inside the nut. Yeah, that would let gear lube leak past the switch all right.

Transmission On the Bench

The transmission splines were dry and need to be lubricated, but otherwise, they look to be in good condition. I had them replaced at about 50,000 miles when they failed. I hadn’t lubricated them at 24,000 miles, so I deserved that 🙁 It looks like they can do with some molylube again.

Tranmission Splines In Good Shape

Last, we removed the rear drive from the drive shaft by removing the four nuts that attach the swing arm to the rear drive.

I cleaned up the transmission, rear drive and the swing arm which was pretty caked with dirt and dried gear lube from the leaking neutral switch. I’m going to paint the swing arm and also do some spot painting of dings on the frame which are a lot easier to get to with the transmission removed.

Rear Drive Removed from Swing Arm

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Silver Ghost Restoration-Part 12 Painting Frame, Subframe, Swing Arm

I finally got decent weather for painting this Sunday, low humidity and temperatures in the low 70’s. I had prepared the frame, sub-frame and swing arm for painting over the past two weeks during the evenings after work. I used body putty to fill in where the paint was chipped from stones and where acid from the battery had removed the paint when the bike tipped over. (Would anyone who owns a bike for 35 years and never had it tip over, please raise their hand? Hmm, is that a hand up way in the back? 🙂 ).

Rear Frame Ready to Paint

It was hard to sand the putty on the tubes since they are round. I found using 400 grit paper and just curling it around the tubes and using light pressure worked. I had to apply the body putty several times to fill in low spots and holes so this took a couple of nights to get the frame and swing arm prepared. Since I stripped the subframe down to the primer, it was ready to go.

I built a paint booth in the garage. I used several plastic drop cloths and stapled them to the joists to create an enclosure around the frame with enough room to paint the swing arm and subframe as well. I taped the seams between the drop cloths in several places to help seal them. I didn’t tape one seam so I could get into the booth. I used clothes pins and rolled the edges of the two plastic drop clothes together and fastened them from the inside with the clothes pins to seal the entry.

Do It Yourself Paint Booth

Do It Yourself Paint Booth

I removed the cars and the other bikes before I painted as spray paint sends small droplets of paint everywhere even though I was painting inside an enclosure.

Prior to painting, I used windex and paper towels to clean all the surfaces and remove any dirt or oil traces. I wore nitril gloves to keep finger print oil off the surfaces. Then, I wrapped all the surfaces on the bike that I wasn’t going to paint with newspaper. Finally, I covered the floor with newspaper as well.

Wrap What Isn't Getting Painted

Frame Read To Paint

Sunday, I taped off the bearings and covered the ends of the rear drive in the swing arm with newspaper and hung them from the rafters. I used wire for the swing arm since its heavy and string for the subframe. I had left enough room inside to hang those behind the bike and could walk around the front and back end of the bike to get to all the parts.

Swing Arm & Subframe Ready To Paint

I used a hat, mask, nitrile goves and a long sleeve shirt when painting. It gets all over you, so covering up is a good idea. I also recommend wearing safety glasses to keep the paint out of your eyes. I opened the back door and cracked open the garage door to get some air circulation to remove the fumes, but not enough to have to worry about dirt and dust getting on the parts. I painted each part with about 4 coats of gloss black enamel paint available at my local auto parts store. I painted 2 coats in the first pass and let that dry for about an hour. I filled a small butter tub with Laquer thinner so I could clean the spay head in between uses to eliminate paint globs.

As I painted, I found the newspaper got very sticky and I was pulling it up when I walked on it. Perhaps, using some wax paper on the bottom of my shoes fastened with duck tape might have prevented that. I’ll have to try that next time when I prime the tank and fenders.

I inspected everything using a drop light after the first two coats and was amazed to see a half dozen places that didn’t get covered well. When painting black paint on top of black paint, its hard to see where the coverage is thin, and it’s especially hard to see when painting tubing. I painted the final two coats starting with the areas that were thin from the first two coats. I kept the final 2 coats light but made sure they wet all the painted surfaces.

Despite covering up, I got paint on my cheeks and forehead, so taking a shower right after you finish painting is a good idea as the enamel takes several hours to really dry and a shower seemed to remove most of it from my skin and beard.

Here’s a picture of the mask I wore after I finished painting. This is a pretty graphic demonstration of why you don’t want to paint without a mask. Most of that would have ended up in my lungs. I suspect that’s equal to a month or two of a 2 pack a day smoking habit 🙂

Why You Wear A Mask When Painting

I’m letting everything dry for two days before touching them. Enamel takes awhile to harden, so its good to be patient and avoid touching the parts so you don’t get finger prints in the paint.

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Silver Ghost Restoration-Part 13 Putting Back End Back Together

I’ve been out of town more than usually over the past couple of weeks, so progress has slowed down a bit.  I discovered that the paint on the subframe didn’t adhere properly – ripples in some places and soft paint in others :-(.

I suspect the aircraft stripper wasn’t completly removed from the subframe.  I took the wire wheel and my hand drill and wire brushed the new paint off the frame.  Then, I washed it in the sink several times and finished it off with windex and paper towels to dry it.

This time I primed first and could see the primer was sticking nicely.  I did a light sand with 400 grit, washed it again and then shot it with several coats of the black gloss enamel.  When I came back from my recent travels, the enamel had no ripples and the subframe was looking great.

While I was out of town, the heads came back from Randy Long at Long’s Custom Services in Pennsylvania.  I originally sent him the head with the cracked fin to repair.  When he received it I called him to talk over the options for the repair.  Since the crack extended past the pin, I had Randy cut the pin off and fix the fin.  Upon closer inspection of the seats, Randy conclued the exhaust valve was buried too far into the head to be in spec.  I decided to ship him the other head and have him replace the exhaust valves, guides, springs and keepers.   Here’s a before, after picture set of Randy’s work.  Very nice repair.

Cylinder Fin Damage

Fin Repair on Head

Heads Back from Randy Long

Today, Sunday, Branden came over and we started working on putting the backend back together.  First, we cleaned the rust off the transmission input shaft and greased it with Honda Moly-60 paste.  The BMW greases don’t have a great reputation, but the Honda Moly-60 is recommended by many.  I used a toothbrush to put a light coat on the transmission splines.  It’s best to coat the transmission splines ONLY and not the clutch plate female splines.  This way, any excess grease is pushed past the clutch plates so any thrown off won’t coat the plates.  I also put a dab on the end of the clutch throw out rod to keep it and where it contacts the clutch plate from rusting.

Adding Moly-60 Grease to Transmission Spline

Greased Transmission Spline

Next, we put the transmission back in the frame and carefully inserted it into the clutch spline.  I put rags on all the freshly painted frame tubes to prevent scratching the paint job.  Here’s Branden getting it lined up.

Sliding Transmission in the Frame

He put the three bolts and the upper right nut back on and torqued them up.  Branden had to leave at that point, so I continued with the swing arm, rear drive and rear wheel.

I cleaned the old gasket off the rear drive and swing arm which took some time.  I found using carb cleaner and then working at the old gasket carefully with a paint scraper and brass brush finally got the 35 year old gasket off.

Next, I mounted the swing arm with the bushings and ran them in as evenly as I could.  Then, using a caliper, I loosened one bushing and tightened the opposite one until the gap was within .02 inch on each side.

Measuring Swing Arm Offset

Next, I torqued the bushings to the bearing preload torque and measured the gap again.  I had to loosen the bushings and readjust the gap slightly and then retorqued to the preload torque.  Then, I loosened the bushings and torqued to the final settings which are lower than the preload.  I measured the gaps again and they were within .01 inch.

Next, I mounted the rear wheel.  I found that sitting on the rear wheel when I took the transmission/drive shaft bolts off keep the shaft from spinning, so I figured it would keep the shaft from spinning when I tighted them.

I mounted the rear drive to the drive shaft.  These splines are lubricated by the gear lube in the drive shaft so you don’t need to grease them.  I rotated the drive shaft until the splines lined up, slide the rear drive on the shaft splines, and then put the nuts on the studs.  There are no torque settings so I tightend the nuts to a reasonable level.

As I don’t have the BMW tool for torquing the bolts that connect the drive shaft to the transmission output shaft, Clem suggested I use some thread lock and tighten with my 10 mm ring spanner until tight.  The bolts and washers are “use once” and get stretched when tightened, so they can’t be reused.   I put the rubber boot on that goes between the swing arm and transmission and then pulled the drive shaft up to the transmission.  Then, I put locktight on each of the new bolts and finger tighted them onto the tranmission output shaft and then leaned into them while sitting on the back tire.

Finally, I pulled the rubber boot over the swing arm and used the large ring clamp to attach it to the swing arm and used the second ring clamp to attach the other end to the transmission.  Here’s the pictures of the bike with the back end reassembled.

Transmission & Rear End Installed Transmission & Rear End Installed

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Silver Ghost Restoration-Part 14 Small Parts & Engine Painting

We have had miserable weather with cold, damp and even snow in Denver for the past two weeks.  We did get two warm days stuck in the middle of each week and I took advantage to complete painting of the small parts and the engine cylinders and valve covers.

For the small parts, I used some wood clamps and some plywood on my saw horses to make a “paint fence” so I could hang the parts.

Small Part Painting

I again had some problems with paint adhering to some of the parts 🙁 , so I had to strip the turn signal brackets and repaint them.

The next warm day, I painted the cylinders and valve covers.  The valve covers have ridges that are not painted.  I thought putting a little oil on them would keep the paint form sticking.  That was not a good idea as the oil flowed down the side of the ridges requiring me to re-clean the parts.  Next, I tried axle grease very sparingly applied to the top of each ridge.  As noted below, that didn’t really work well as the paint became very sticky and was hard to remove. I primed the parts and then finished up with engine paint rated to 500 degrees temperature.  I taped off the base of the cylinder, the ends of the push rod tubes and the  top of the head where the cylinder gasket goes to prevent getting paint on these surfaces as they have close tolerances.  I also stuffed the cylinder bores with newspaper and taped off all the holes in the top of the heads.

Here’s the parts after painting.

High Temp Engine Paint

I found that the best approach for cleaning paint off the ridges on the heads was to use a Dremel tool with a coarse sanding cylinder to remove the paint from the top of the ridge.  This also let me remove some gouges and pits in the aluminum. I masked off the covers around the ridges with masking tape to prevent mishaps.  After removing much of the paint with Dremel tool which really gummed up the sanding cylinders (I used 5 of them 🙁 ), I used a sanding block with 220 grit to get all the last bit of paint off and then finished up with 600 grit to polish the aluminum.  Here is the before and after pictures.

Valve Cover Painted

Valve Cover Detailing

Finally, I baked the parts in the oven at 350 degrees for 20 mins.  I opened windows and doors to let the fumes escape. My wife, who is a saint, only mentioned that they were “stinky” as they baked …  “Nothings quite so loving as something in the oven” 🙂

Backing Cylinders and Valve Covers

I believe I have all the parts painted other than the fenders, tank, side covers and fairing which will be painted Smoke Silver.  That promises to be an adventure 🙂

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Silver Ghost Restoration-Part 15 Mounting Front Wheel & Subframe

When I had the front end rebuilt, I had 11 rib fork boots not the standard 13 rib.  So, I removed the tubes and mounted the correct 13 rib boots.  I also cleaned up the snowflake cast front rim and the disk brake rotor assemble and had repainted the brake caliper which was showing aluminum instead of the original black paint.

Here are the pictures of the front end with the incorrect 11 rib and the correct 13 rib fork boots.  It looks much better with the correct ones installed.

Before Tranmission Removal

Front End Forks w/ 13 Rib Boots

I loosely mounted the fork brace and then mounted the front wheel .  I pushed up and down on the forks a couple of times to ensure alignment and then tightened the axle nut and locking bolts.  Again, I pumped the front forks up and down and then tighted the fork brace bolts to the correct torque settings.

I bought new disk brake pads and also had to buy a new brake pipe as corrosion had made one of the nuts too small to fit a standard 10 mm ring spanner.  The two pads are different.  The one that goes into the piston side (right one in the photo) of the caliper has a small hole in it and the fixed pad (left one in the photo) has two raised castings that center the pad in the circular caliper cut out.

Disk Brake Pads, Right w/ Pin Hole, Left w/ Raised Pad

The brake pad kits come with a new O-ring that goes inside the center of the caliper piston as shown and a new clip for securing the fixed pad onto  the back of the caliper.

Disk Brake O-ring in Piston

Insert the pad into the piston first. The curved end of  the pad goes to the back of the caliper.  Then, put the pad into the fixed side of the caliper and secure it with the clip on the back with the open ends facing down as shown.

Disk Bake with Pad Inserted

Disk Brake Rear Pad Retaining Clip

Next, I mounted the caliber to the fork using the excentric pin to hold it in place.  Finally, I connected the new brake pipe to the braided steel brake line.  Here’s the completed front end and wheel with brake caliper.

Disk Brake & New Brake Line

Front Wheel with 13 Rib Fork Boots

Front Wheel with Disk Brake

I spent a couple of hours polishing the aluminum engine cases with Autosol metal cleaner, metal polish and finished up with Aluminum oil.  Now it really matches the transmission and rear drive and has a nice satin patina to it.

Finally, I mounted the subframe. I found mounting it using the bottom bolts first makes it easier to force the top legs into the top of the spine.  Then I used a piece of wire and threaded it through the rear hole to the front hole in the subframe.  I wrapped the wiring harness with duct tape and twisted the wire around that and pulled the wire harness back through the subframe tubing to the rear.   Its all ready for the rear turn signals, but I have to finish painting the rear fender before I can mount them as they attach to the fender.

Pullin Wire Harness with Wire & Duct Tape

Here’s the Silver Ghost with the subframe mounted to the frame along with the key lock and the side handle for lifting the bike onto the center stand.  It’s starting to more like a motorcycle. I just need to slap the rear shocks back on when I get the chance.

Rear Assembled

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Silver Ghost Restoration-Part 16 Shocks, Controls, Handlebar, Wiring

The past week I’ve been working on a number of items.   First order of business was to put the shocks back together and mount them.  I clamped the shock in a vice an put the preload adjuster, retainer and shock together with the tighter windings of the spring at the bottom.

Spring - Tighter Windings at Bottom

In lieu of the BMW shock spring compressor, I use  two 1 inch hose clamps to compress the springs so I can put the top shock mount bracket on.  Thread the hose clamps through three of the spring coils near the top and then tight to compress the springs leaving a clear space between the top of the spring and the bottom of the mounting bracket.

Using Hose Clamps to Compress Springs

I could push the aluminum cover down a bit more to insert the 10 mm wrench on the shock rod and a screw driver through the eye bolt to tighten the top mounting bracket.

To mount the shocks, I used a jack stand and some wood blocks to hold up the rear end so I could insert the top bolt on the right side shock.  Since that side has a stud for the bottom mounting, its easier to mount the right side first.

Propping Up Rear for Shock Mounting

With the rear shocks mounted,  I took apart the instruments, controls and handlebar to clean them up.  I also needed to remove the Windjammer V wiring harness from the headlight shell so I could reinstall the original headlight wiring harness.

Steering Parts & Instruments Removed

Windjammer Wire Harness Removed

I painted the headlight “ears”, and cleaned and polished the mounting hardware before putting the R90S turn signal brackets and fairing mounting brackets on.

Cleaned Handlebar parts

Fairing Bracket and R90S Turn Signal Bracket

I wired in the turn signal wires and the old front headlight wiring harness and the neutral switch that allows you to start the engine when the clutch is pulled in.  I took some time reviewing the wiring diagrams to find out where the connectors go inside the headlight shell.  I also had to modify some of the connectors to the correct “L” shaped connector with insulator boot. It does look like “wiring spaghetti” inside the headlight shell 🙂

Old Headlight Wiring Installed

The final task was to mount the speedometer/tach, handlebars, controls and atach the new throttle cables and the existing clutch and front brake cables to the levers.  It took some time and couple of disassemble/reassembly tries to get the wiring and cables routed correctly.  For some reason, its too easy to get one thing going the wrong way with that many cables and wiring harness to contend with.  Here’s the final handlebar and control assembly’s mounted.   The new paint stands out compared to the dulled plastic of the switch assembles.  I’ll try more Amour All and see if I can brighten the plastic on the controls.

Instruments Installed

Right Control Assembly

Handlebars, Instruments & Controls Installed

Original Headlight Installed

At this point, the engine top end, carburetor rebuild and new electronic ignition installation are the remaining mechanical tasks.  And,  the painting project of course, is still left to be done.  But, the Silver Ghost is coming back together.

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Silver Ghost Restoration-Part 17 Carburetor Rebuild, The Good, The Bad & The Ugly

Over the Memorial Day weekend, I took on the task of rebuilding the carburetors.  The right side carb had a broken float pin boss and I had to get a used R75/5 carb body 5 years ago to get it running again.  The right side has not been happy and when the heads and valves were redone, the right side exhaust was in worse shape than the left which are signs of lean running on the right side.  With 103,000 and 35 years on the left side carb, and no full rebuild in that time (new floats and float needles of course, but no rebuild) it was time to get them back in condition.

Video: Rebuilding Bing CV Carburetors

I made a general video about rebuilding Bing Constant Velocity (CV) carburetors. The technique is applicable to 64/32 (32 mm) and 94/40 (40 mm) CV carburetors. There are some differences in certain models including the choke and throttle linkages and the spring added to the top of slides in some models. So, you will see all the specific details in this write-up.

VIDEO: Rebuild Bing 94/40, 64/32 CV Carburetors

To keep parts together, prevent confusing the parts from the left with those from the right side and to always have a correctly assembled carb to refer to, I rebuilt them one at a time starting with the right side.  Since I was going to reinstall the original 75/6 right side carb, I would be stripping all parts off the old 75/5 carb body, replacing with new parts in the rebuild kit, and reusing the other parts.  The R75/6 body had been sent to the Bing Agency to repair the broken float boss.  Here are the before and after pictures.

Bing Carb - Broken Float Hinge Casting

Bing Carb Float Bracket Repair

Although Bing cleaned the carb, I polished it up a bit more with aluminum cleaner, steel wool and metal polish while I waited for parts to soak in solvent.

The first step was to remove the enricher from the R75/5 body taking out the 4 machine screws.  As you can see in the picture, this is the Bad part — as in dirty.  But it gets worse.

Enrichener Removed

Next, I took off the float bowl … and now you can see the Ugly part … a nice bunch of glop in the bottom … not a good sign of a healthy carb by any means.  I’m suspicious that the float was starting to dissolve which can happen with our methanol laced fuels.  Corrosion is also clearly evident on the washer underneath the main jet in the center of the carb and the gasket between the float bowl and carb body is complete toast.

Right Side-Gooey Surprise

I focused on the enricher rebuild first.  I dissembled it, and took pictures of the parts order so I wouldn’t make a mistake.  I also have the Bing Agency carb book with full exploded view diagrams is also helpful.  I’ll refer to part numbers in this diagram in the following material.

Enrichener Disassembleed

I removed the old O-ring (pretty cracked) (#26) and soaked in parts washer solvent for several hours.I cleaned up the housing and lever using a wire wheel, aluminum cleaner and then metal polish.  I used some masking tape to cover the threads of the disk (#47) to make it easier to get the O-ring (#49) on and not tear it in the process.  I have some steel picks, one of which has a “C” shaped end that I hooked under the O-ring so I could pull it over the threads and onto the slot.

Enrichener Tape on Threads for O-ring

Enrichener O-Ring on Shaft

I found details in Snowbum’s on-line BMW reference material on how to ensure the enricher is assembled correctly.  There are two articles as well as another on the R75/5 Bing carburetor.  As is the case with his writing, read slowly and carefully and be prepared to be told the same thing three times in different places and different ways.  The right side housing has the curved passage on the right.

Enrichener-Right Side Cover

You should confirm you have the correct disk.  The inside of the shaft is stamped with “R” for right and “W” for wrong … :-), actually, it’s “L” for left.

Enrichener-Right Side Disk

Then the disk is inserted as shown, with the slot at the 8:00 position and the little holes at the 1:00 position.

Enrichener-Right Side Orientation

Then I assembled the housing using the new gasket (#50) between it and the carb body.  I put a small amount of silicone grease on the O-ring and a tiny amount of antiseize on the threads of each of the screws (#51).  Note there is a dimple on the shaft which is on one side of the shaft.  This should be closer to right side on the right carburator.

Enrichner - Shaft Orientation

The handle goes on the shaft with the nut (#52d) to attach the choke cable facing to the outside and the shaft handle between the two verticle pins with the shaft pointing to the fuel spigot of the carb.

 

Enrichner Assembled

I put a tiny bit of antiseize on the brass threads of the shaft and then tightended up the nut.

The next step was to remove the throttle linkage (#27, #28), spring (#35) and throttle linkeage bracket (#31).

Throttle Assemble Details

Then I remove the throttle plate (#23) and throttle shaft (#24).  The screws (#25) holding the throttle plate to the shaft are peened over and are hard to remove.  I was not able to remove one of them.  I ground off the end of the screw on the back side of the throttle plate with a grinding stone on the end of a Dremel tool, and drilled a pilot hole for my smallest easy out and extracted it.  The carb rebuild kit comes with new screws, so no worrries.

Throttle Plate w/ Screws

Throttle Plate - Drilled out Screw

I soaked the parts in solvent for several hours and then cleaned them.  I polished the throttle linkage parts and springs with a wire wheel, steel wool, aluminium cleaner and then finished them off with metal polish.  I replaced the O-ring on the throttle shaft using tape over the threads.  I put a bit of silicone grease on the O-ring.  Then I pushed the shaft back into the throttle body.  It took a couple of tries to get the throttle plate into the slot in the shaft, so be patient and don’t force it.  I found assembling the throttle linkage bracket (#31) into the groove on the throttle shaft and then tightening the bracket screws to the carb body ensured the shaft would not bind.  I didn’t do that the first time and it bound up as there is some laterial play in the throttle shaft.  I used lock tight on the throttle plate screws to ensure they wouldn’t come loose … if they do, they go right into the engine 🙁  I also put a tiny bit of grease on the groove in the throttle shaft to keep things turning smoothly.

Next I removed the top, pulled out the slide with the jet needle and removed the metal ring (#17) holding the rubber diaphram to the top of the slide.  There is a new jet needle (#3) in the rebuild kit and a new needle jet (#4).  The needle vibrates and wearing the needle jet and the needle.  I could see grooves in the needle.

Then, I took out all the jets from the bottom of the carb.  When I reassembled the main jet, it cracked in two.  It likely had a crack in it before hand.  I suspect a cracked main jet didn’t help carburetion any  🙁   I have extra main jets, so no problem.

Broken Main Jet

Each of the jets I removed (#7, #5, #1, #2, #3, #10) was very dirty.  Here is the crud that was inside the needle jet (#3) and the atomizer (#2).

Gummed Up Needle Jet

I had read on Snowbum’s posting that Berryman B-12 Chemtool was very good at removing crud and fuel varnish, but extremely nasty stuff.  I bought some and wore my nitrile gloves when handling it.  When I fished the parts out of the container, the nitrile started to wrinkle … the next day, the finger parts had completely dissolved … nasty indeed.

After all the internal jets were cleaned, I put new O-rings on them again using the masking tape trick and “C” shaped steel pick to pull them into the groove on the jets.  I broke one, but my handy Ace hardware had a metric replacement :-).  I used a tiny bit of antiseize on the threads as they all have brass to metal contacts.   I installed the new needle jet (#3) and atomizer (#2).  The Bing exploded view diagram (and the picture I took) helped me make sure these went together in the right order.  I installed the new float (#40), float needle (#4) and float hinge pin (#1  from the rebuild kit and then put in the new cork gasket (#46) into the groove in the bottom of the float bowl.

Bottom Side

I reassembled the slide (#13) with the new diaphram (#16) from the rebuild kit and a dab of antiseize on the screws.  I added the internal spring (#22) which was not part of the original carb assemble.  Clem supplied these and said adding them would improve gas mileage.

New Slide Spring

Then, I put the top (#20) back on and put a tiny amount of antiseize on the screw (#21) threads.

Now for the Good part.  Here is a before after series of pictures comparing the rebuilt right side carb to the yet to rbuild and clean up left side carb.  Definitely night and day.

Before & After

Before & After

Before & After

Then, I did it all one more time on the left carb.  Both were in need of attention, so I am very hopeful they will operate much better and the bike run a lot smoother.

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Silver Ghost Restoration-Part 18 Zen and The Art of Motorcycle Rebuilding

I started on this project last October and have been chipping away at it as time permitted.  Last week, I had a four day weekend and spent time preparing for painting, aka, priming and sanding.  This has taken much longer than I expected, and I’ve been recalling Robert Pirsig’s “Zen and the Art of Motorcycle Maintenance“.  I’ve experienced several personal “gumption traps” and found that “being in the moment” is not easy to accomplish in a consistent manner.

The paint preparation phase has exposed a couple bad habits I have.  The first is hurrying, the second is not thinking it through and the third is pushing to complete when I should take a break.  These are related, and if I recall, are called out by Pirsig as examples of gumption traps that impede attaining quality.

Hurrying usually results in getting “behinder” due to mistakes and the rework they require.  On top of that, you’re attitude is not postive due to your inner voice of self critisim getting pretty loud.  The fun factor goes way down.

If you don’t stop and visualize getting from what you have to what you want, you can find the path you take is the wrong one, or you aren’t taking the shortest path to do the work.  This is more the case when I have been working on disassembly and assembly of the Silver Ghost, but I find it happening in paint preparation as well.  For example, I’ve forgotten to clean spray nozzles, not had the gloves on, forgotten to clean the parts with Windex prior to priming and each of those are the result of not thinking about how to go from what I have in front of me to what I want as a result BEFORE starting the work.

I also find that “getting done” is a slippery gumption trap.  Getting done, of course, has value and does provide gratification.  But, the journey also has great reward, and a journey done well has an even greater sense of accomplishment.  I’m starting to figure out when the “let’s get done” motivation is out of control.  And every time I don’t listen to that inner voice that says “Hey, you’re getting tired of what you are doing, take a break”, and keep on working, inevitably s&^%t happens.

I think there are days when you should not work on a project.  This past Monday was one of those.  I managed to break the coffee pot, assemble something backwards and put get my finger prints in wet primer … all in about an hours time.  I quit for the day at that point.  It seems that Monday was not a day where I was “in the moment”; perhaps I distracted with thoughts of a family get together later that day or the thoughts about the impending return to work drowned out being in the moment.  For what ever reasons, the Zen required for good quality was not in evidence.

A final observation I want to pass on has to do with our recognition of and pursuit of quality.  Paint preparation really brings quality into focus: many small things add up to good quality.  I’ve sanded several areas and had to refill them because the surface was not right.  Each time I re-primed those areas, I’d think “There, that’s got it”.  And then I’d re-sand it and see another defect, and I’d say “Well, that’s not enough to make any difference”.  But, the next day, I’d look at that area again, and it was clear it wasn’t up to snuff.  So, I’d go back and fill it, prime it and sand it again.

We do recognize quality in an instant, but we also have a lot of built in “avoidance” behaviors that let us pretend we have achieved it when we haven’t.  The pursuit of quality demands an ego-less perspective on our own work, and that isn’t easy to achieve.  There is an absolute honesty required about your work if you want it have quality.  Achieving that honesty is worth the journey.

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Silver Ghost Restoration-Part 19 Engine, Carbs, Exhaust

Over that past couple of weeks, I got the pistons, cylinders, heads, carburetor and exhaust back together.  It’s almost looking like a motorcycle again 🙂

I cleaned the carbon off the pistons using a wire wheel prior to putting the rings back on.

Carbon Build Up on Pistons

Before.

De-carbonized Pistons

After.

I put the new rings back on by hand.  The kit has all three rings clearly labeled.  Be sure the “top” on the rings goes “up”

Ring Kit

Ring kit.

Top of Ring

“TOP” is engraved on the top side of the ring.

Then, I heated the pistons in the oven (175) and put the wrist pins in the freezer to make it easy to push the pins into the pistons.  I bought a new set of C-clips and inserted them being sure the gap in the C-clip didn’t align with the cutout for removing them.

C-clip On Piston

C-clip covering the cutout in the piston.

Piston on Connecting Rod

Wrist pin assembled onto Piston a nd connecting rod.

Next, I assembled the push rod tube rubbers onto the ends of the tubes aligning them as shown.

Push Rod Seals

Push rod tube rubbers aligned.

Then, I put the base gasket on using Hylomor as the sealant on both sides of the gasket.  Be sure the holes in the gasket align with the holes in the base of the cylinder.

Base Gasket w/ Sealer

Base gasket with Hylomar sealant before smoothing it out over the gasket.

By hand, (I don’t have a ring compressor) I pushed the cylinder over the piston.  You can do this by hand if you are very patient and go slowly so you don’t break a ring.  I found using two wood sticks made it easier to compress a ring on one side, then I would wiggle the cylinder over the ring on that side and then press the opposite side into the ring gap and wiggle the cylinder past a ring.  Easy and slow does it here.

Assembling Head

Cylinder over the piston.

Next, make sure you get the head gasket aligned the right way so it doesn’t cover the push rod openings.

Incorrect Base Gasket

INCORRECT – gasket covering push rod tube holes

Correct Base Gasket

CORRECT – no obstruction of the push rod tub holes.

Next, attach the head by sliding it over the cylinder studs and put the push rods into the push rod holes.  Then, add the rocker arm assemblies and using a cross-over pattern, tighten the nuts on the cylinder studs to pull the cylinders down onto the engine.  Check as you go that the push rod rubbers are aligned with the holes in the block, or you will crack them and have to replace them.

Inserting Push Rod

Inserted push rod.

Assembling Heads

Rocker arm assembly attached to cylinder studs.

Assembling Heads

Cross-tighten nuts on cylinder studs to pull cylinder into the block.

Next, follow the torque tightening sequence and tighten the heads down.  Torque is brought up in stages, not all at once.  When that’s done, set the valve clearences, add the valve covers and move on to the other side.

Cylinder & Heads

Cylinder & Heads

I added the carburetors using the rubber spigots and then assembled the new exhaust system.  I found that assembling the muffler to the header first was the best way to go.  I had some troubles with one of the inserts that goes on the header pipe as it wasn’t round.  I finally got it back into shape.  Keep all the connections loose and attach the muffler to the rear mounts.  Then, be sure the header is pushed all the way into the head and twisted so the cross over pipe goes on.  This took some fiddling, but it finally goes together.  On the right side, I had to remove the brake peddle and grind a little off the top of the peddle casting so the peddle would move freely.

Right Side - Almost an MC Again

Right Side.

Front - Cylinders and pipes

Front showing cross over pipe.

Left Side - Pipes & Carb

Left Side.

I’m replacing the choke cables and have to wait for them to come in before putting the air cleaner and housing back onto the engine.  That will complete the engine assembly.

Next up, paint preparation and finally, shooting the paint.

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Silver Ghost Restoration-Part 20 Painting The Body Parts

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UPDATE: The Paint Work I Did Here Failed. I Learned That the Primer I Used Disolved When The Glasurit Paint Was Applied. DO NOT USE SPRAY CAN PRIMER WITH PROFESSIONAL PAINTS. Read This Part Of The Project As A WARNING.

As With Most Things I Try For The First Time, I Make Mistakes And Learn Something I Apply The Next Time I Do It. That Is Called “Gaining Wisdom”. 🙂 

I Plan To Repaint The Bike With The Correct Primer And Post That Material When I Am Done.
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WARNING:
If you use professional two-part primer and clear coat, you are going to be exposed to chemicals that can permanently damage your lungs, brain and eyes. The damage is cumulative and irreversible. I did the paint work on three bikes (this one twice and the R75/5 project) using a lower face mask with filter. I will NOT paint that way again. If I ever paint with two-part paint systems again, I will have a full body suit and full respirator mask with separate oxygen source and complete skin coverage. ANYTHING LESS IS ASKING FOR PERMANENT DAMAGE. As I get older, I occasionally get wiser 😉

As noted in an early chapter, the cost of having the body parts painted by a professional caused me to head towards doing it myself.  I wasn’t afraid of learning by doing, which is another way of saying making mistakes and fixing them.  So, far, I’ve gotten my money’s worth 🙂

I have a friend, Brian House, who has rebuild several vintage English motorcycles and does his own painting.  So, I’ve borrowed equipment and knowledge freely from Brian.  He does his painting “on the back porch”, no paint booth thank you very much.  He uses lacquer and does a lot of sanding between coats to get the smutz (junk) out.

Okay, I have a garage bay, so I created a simple paint booth when I painted the frame.  I rebuilt that booth again with a 3-side design so fumes would not build up.  I picked up a roll of painter’s plastic (12 feet wide) at my local paint store and stapled it to the rafters and taped it to the floor.  It was big enough that I could still park my R1150-RS when not painting as I figured I’d need the booth for a couple of days.  It turned out to be needed a “little longer” than that.

Double Duty Paint Booh
Double Duty Paint Booth.

I added a simple parts stand I had used earlier.  The vertical 2×4 posts fit the center of the tank and the inside of the fenders to hold them steady.  I had plenty of room to move around inside without fear of tripping over things or bumping freshly painted parts.

Paint Booth - Parts Holder
Paint Stand.

Light is your friend.  So, I picked up a 1,000 watt halogen work light with stand for less than $30 at my local Home Depot. Things are a bit rocky with the stand, but the light is great.

Paint Booth - 1000w Halogen Lighting
Configured for painting with 1000 watts of Halogen task lighting.

All the parts had the final primer coat wet sanded with 600 grit paper.  I cleaned the parts with paper towel and Windex to remove lint, finger prints and any other contaminants (or at least I thought I did.  See below.).

The paint kit was ordered from Holt BMW, the US supplier of Glasurit paint that is used by BMW.  Holt also paints BMW bikes for restoration so I called them and spoke with Kent who is their painter.  He provided lots of tips and sent me a pint kit for Smoke Silver.  It has a pint each of silver, black and clear coat, 1/2 pint of clear coat hardener and 1 1/2 pints of reducer.  I picked up a pint of cheap lacquer thinner at my local Ace Hardware for clean up.  The paint kit cost about $330 shipped, so you don’t want to waste it or make too many mistakes and have to buy more.

Holt BMW - Smoke Silver Paint Kit
Holt BMW Smoke Silver Pint Paint Kit.

I borrowed Brian’s compressor and paint spray gun.  I had to run the compressor on a separate circuit from the halogen lights as the lights draw 10 amps and the compressor pretty close to 15 amps.  Don’t ask me how I figured that out 🙂

Compressor - 2Hp, 4 Gal 3 SCFM @ 40psi
Low cost compressor for painting.

I practiced using the spray gun with cheap paint (Duplicolor $25/pint ready to spray) from my auto parts store and got the hang of the gun and setting the paint flow mixture on the gun.

I made a paint test board using some scrape 1/4 inch masonite and covered it with newspaper.  I sprayed that first to adjust the paint flow and compressor air pressure until I got a “medium wet” covering on each pass.  Its important to always test spray like this each time you start painting and make any adjustments before you put paint on parts.

For painting, Kent advised a 50% mix of thinner to paint.  To be clear, that means if you have 1 oz of paint, you add 1/2 oz (50% of the paint volume) of thinner.  I used a dark room plastic measuring cup to mix the paint and popsicle sticks to stir the thinner so it mixed evenly with the paint.

Painting requires a respirator in my opinion.  I found one at my local Sherwin Williams store that comes with disposable filters to keep you from breathing the fumes.  I work in a long sleeve shirt, saftey glasses, baseball cap and rubber nitrile gloves when painting to keep down the paint on my skin.

The silver was laid down in 2 coats.   Wait for the first coat to “flash” which is when it goes from shiny wet looking to dull.  Then you can spray the 2nd coat.  Kent said you could also do a light 3rd coat at 45 degree angle to help hide any streaks as silver is very unforgiving.  On some parts (fairing and tank) I did need the light 3rd coat.

When I painted with the gun, I kept a small cup of lacquer thinner (the cheap Ace Hardware stuff) in a cup.  When I finished a coat, I would detach the paint cup from the gun, stick the paint tube in the cup of lacquer thinner and spray it through the gun to keep the very small internal passages clean and to prevent paint from drying in them.

It took a while to finish the silver coat.  I kept the left over silver paint reduced at 50% in a clean new 1 Qt paint can I got at my Ace Hardware.  I could mix up 4 – 5 oz of final mix that way and not waste paint.  As becomes clear later, I had to repaint some parts, so saving the reduced silver was the right idea.

Note, a pint of silver is barely enough to paint all the parts and allow a little left over to fix mistakes … I got my fingers in the paint, brushed a part with my sleeve, and had to sand out the error and touch up.  Here’s the parts with the silver coat.  The R75/6 is under the plastic to keep it from picking up any of the paint particles.

Parts - Silver Coat Done
Silver Coat Complete.

The next day, I started to paint the smoke layer using the black paint.  It is reduced at the same 50% rate as the silver.  Kent said to dial back the paint volume, dial up the pressure (45 psi) and use the trigger (it increases paint flow as you pull more) to get a very light layer of black.  I practiced and pretty soon was ready to start.  I visualized where I wanted the edge to be, moved over a bit (to where the full black would be) and started a pass.  As I saw the paint lay down on the silver, I’d adjust my trigger and my rate of sweep and then move over to where the edge would be so it was a very light layer in a straight (or for the fairing, curved) line.  Then, I’d continue adding paint in successive passes towards the black edge building up the layers as I went.  It took 5 -7 passes to build up the black at the very darkest areas.  Here are the side covers to show how the faint “smoke” edge follows the contour lines of the cover.  You can see the light smoke on the silver panel.

Side Covers - Smoke Silver
Black “Smoke” Layer on Side Covers.

I made a mistake on the front fender and had to reapply the silver down the middle and then come back and reapply the light black layers to fix that.   Here’s the other parts with the black smoke coat applied.

Tank shot w/ Smoke Silver

Fenders - Smoke Silver
Black “Smoke” Coat On Fenders and Tank.

Now, the problems started.  I had taped the fairing holes to prevent the silver from getting on the inside of the faring which I had painted black.  As I took the tape off, the silver coat lifted.  It failed to bond to the primer correctly.  So, I had to sand out the silver to feather it, and re-shoot it :-(.

Fairing - Paint Failure
Silver Paint Failure on Fairing.

That set me back a day.  But I finally got the fairing painted with black and got a nice circular edge between the silver and smoke areas of the black.

Next, is the clear coat.  That requires a hardener at a 40% ratio and thinner at a 10% ratio.  That means, if you use 2 oz of clear coat, you will need 0.8 0z of hardener and 0.2 oz of thinner.  I used milliliters which also are marked on my dark room measuring cup.  500 ml of clear coat, 200 ml of hardener and 50 ml of thinner.  Now, you can’t save any unused clear coat like you can unused paint as the hardener turns it into a solid mass in a couple hours.  So, try to mix up what you are going to use and not waste a lot of it.  Kent said 2 coats of clear works well.

By this point I had a little bit of reduced silver paint left, a bit more of reduced black and more than that of the clear coat left.  I had taped the fairing over the holes again and this time, when I removed the tape, all the paint pealed off 🙁 :-(.  It once again had not adhered and could be pealed off in strips.

Paint Failure
Paint Adhesion Failure on Fairing.

It was a large downer when I saw that.  I pulled all the paint off.  I re-sanded the primer with 400 grit, and then shot two new primer coats on top.  As I thought about what might be going on, I remembered that at one point I had been using dish detergent in my water for final sanding.  I was suspicious that this left a residue that kept the paint from adhering.  I final sanded with wet 600 grit and cleaned it all again with Windex and paper towels.   I re-shot the silver, black and clear coat over the next couple of days and was back to getting ready to buff out the clear coat.  At this point, the silver is all gone … so I was hoping I was good to go for buffing out the clear coat.

And then, one of the side covers also peeled 🙁 :-(.  I spoke with Kent and learned that he uses a special primer that has a hardener in it.  I am not.  I am using Ace Hardware Krylon primer.  Maybe that’s the issue.  His primer is about $100 a quart and I suspect I’d need more than one.  I need more silver paint and decided to order another pint paint kit in case I have to start over again and repaint all the parts.  (I’m an eternal optimist.  Maybe the other parts are fine …)

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And, in fact, it’s the primer I used that is the problem. It is a one component primer. It is being dissolved by the Glasurit sovlent in the base coat so the silver doesn’t really adhere to the primer, but floats on top. I should be using 2 component, or 2K primer, that has a hardener added to it. I will use the Glasurit 2K primer when I repaint the bike. As I write this it is 2014 and I am preparing to repaint the bike. This paint job stayed on the bike for 3 years and continued to chip along the edges and developed a complete delamination around one of the petcocks.
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But, I’m going to conduct an experiment with the side cover.  I used the Krylon primer again and carefully cleaned with windex (which Kent has used in the past, so that’s likely not the problem).  On half of the side cover I applied a Rustoleum “Primer Sealer” at $4.25 per can, its a lot less than Kent’s special primer with hardener.  I’ve wet sanded out the side cover ( no detergent in the water) with 600 grit. When the paint arrives, I’m going to shoot two coats of silver on the cover and wait over night.  Then I’m going to put masking tape on it and peel … repeatedly … and see what happens.  I’ll certainly learn something useful and can proceed accordingly.  Stay tuned …

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Silver Ghost Restoration-Part 21 Finished on Halloween

This evening, Halloween, I got the Silver Ghost running again.   That’s one year to the day after I took it to BMW of Denver for the first step, straightening the front forks.

Finish Painting

I had paint failures along the way.  I had to repaint the fairing, side cover and rear fender (so far).  I’m not certain what the problem was, but suspect using dish detergent in the final sanding of the primer could have been the reason.  I suspect I’ll have other parts peal, but for now, everything is staying painted :-).

I also used 1500 grit when I sanded out the clear coat, and that was a mistake.  This is too coarse and I had many hours of final sanding of the tank clear coat trying to remove the scratches.  There are still one or two deeper ones.  I decided to stop sanding it out with 2000 and then 2500 grit as I was afraid I’d cut completely throught the clear coat.  As I paint in an unheated garage, I’ve run up against the end of “painting season”.

I bought another paint kit from Holt BMW and only used a small amount when I redid the rear fender.  If I get more peeled parts, I can strip them in the spring and reshoot.

You can see in this picture how the finish sanding with 2000 grit and then a light 2500 grit coat removes “orange peel” and small defects in the clear coat.  On the left is the final 2500 grit, transitioning to the in progress 2000 grit and finally the unsanded clear coat on the right.

Sanding Clear Coat
Final Sanding of Clear Coat.

I buffed out the sanded clear coat using 1500 grit polish and then scratch remover.  I used a drill with buffing pads, one for each.  I likely spent 20 hours buffing out the clear coat.  As I said, the gas tank had deeper scratches.  I had to back up and sand out the deeper scratched areas with 2000 then 2500 grit, buff with 1500 polish and then the scratch remover.  Several sections required 4 or 5 repetitions of this to finally get the scratches out of the clear coat.

Assembly

I started at the rear and worked my way forward.  I removed the rear tire and mouted the rear fender using new rubber bushings.  As I have an oversized rear tire (4.00 instead of 3.5 inch), I had to carefully slide it back in using a clean shop rag to protect the paint on the rear fender.

Next, I added the rear taillight assembly, turn signals and license plate bracket.

Then, I mounted the seat.  I found putting the rear hinge on the seat pan and tightening the screws fully and putting only one screw in the front hinge is the best way to mount the seat.  You can swing the front hinge on the screw pivot point to get the hinge on to the bushing.  Then you can get the other two front hinge screws inserted and tighted as there is a frame cutout to let you access one of the screws.  Here’s the back end and seat assembled.

Rear Back Together

Seat & Rear Fender
Rear End Assembled.

The side covers were next.  I cleaned them with dish detergent, rinsed, and then sprayed with windex and wiped clean before I mounted the “750cc” decals.  I had to adjust the side cover clamps on the subframe as they were too tight.

Side Cover
Side Cover With Decal.

The gas tank has a gold pinstripe.  I am not confident the tank won’t peal, so I decided to use vinyl pinstripe tape instead of painting them on.  I used 1/8 inch pinstripping.  Again, I washed the tank with dish detergent, rinsed and finshed up with windex.  After I got the pinstripe on, I added the BMW badges to the tank.  I think it looks “kinda nice” 🙂

Tank

Tank
Gas Tank With Emblem and Pinstrip.

I worked on the fairing next.  I used 1/4 inch pin stripe, but I think that maybe too wide.  When I repaint the fairing again, I’ll opt for 1/8 inch instead.  Mounting the fairing was  time consuming.  Getting the lower holes over the turn signal brackets was not easy.  And, there are a number of rubber grommets that hold the lower portion of the fairing on the turn signal stalks.  There is a rubber gasket the goes over the headlight and inside the head light hole in the fairing.  And there is the bracket on the fork tubes with a steel stem that mounts the top of the fairing to the fork tubes.  Keep things loose until you get the hole in fairing adjusted around the headlight gasket and then tighten the nuts on the steering head  bracket.  Finally, I put the turn signals on the stalks, wired them up and put the covers back on.

Fairing & Tank
Fairng & Tank Mounted
Fairing Mounted.

Finally, I took the front wheel off, and mounted the front fender.  There is a chrome bracket to hold the rear of the fender and again, there are rubber grommets that protect the fender from the steel brackets.

Cylinders & Front Fender

Finally, I bought a new windscreen from Gustafsson , opting for the 7″ rather than stock 3″, in light smoke color.  The mounting holes are pre-drilled and they lined up perfectly.

Side View

Side View
Gustafsson Plastics Faring Mounted.

The last item to go on was the bar end mirrors I got on Ebay.  These add a nice cafe racer touch and really look very nice.

Cockpit & Bar End Mirrros
Bar End Mirrors.

Punch List

Now that the plastic parts were back on the bike, I had to handle a number of final “punch list” items including.

  • Connect battery and charge it up
  • Add brake fluid to the front brake and bleed it.  Then adjust the calpers
  • Add engine oil, and gear lube to the transmission, final drive and drive shaft.
  • Test the electrics. (I had to fix one rear turn signal, loose wire) including starter motor
  • Clean, polish and install petcocks and add gas lines from petcock to tee fitting
  • Install coils, spark plug wires and spark plugs
  • Adjust carburators to initial settings
  • Add 1 gallon of gas to the tank

Will it Run?

So at 7:30 pm, its time to find out if the Silver Ghost will start.  I turned the petcocks to reserve, and found a bit of leaking which was quickly fixed by snugging up the nut to the gas tank.  I pulled the plugs and checked for spark.  None.  Hmmm … I disconnected the battery pulled the timing cover, and there was the loose wire to the condenser.  I had two black wires when I installed the coils and  had pulled the condenser wire to test which one was it, but forgot to reattach it.  That was easy.

After reattaching the battery cable, I pulled in the choke, hit the starter and in 3 spins the Silver Ghost came back to life.

HAPPY HALLOWEEN Silver GHOST …. ITS ALIVEEEEEE !!!!

2015-2016 Refresh Projects

Well, five years after I completed the build, and in October 2015, I decided it was time to fix some problems and do some other projects on the Silver Ghost. The trigger was painting the R75/5 which provided the opportunity to redo the paint on the Ghost which was peeling and delaminating. The cause was using rattle can primer with Glasurite paint. The primer failed because the strong solvents in the base coat dissolved it. Oh well, live and learn and I got five years out it.

WARNING:
If you use professional two-part primer and clear coat, you are going to be exposed to chemicals that can permanently damage your lungs, brain and eyes. The damage is cumulative and irreversible. I did the paint work on three bikes (this one twice and the R75/5 project) using a lower face mask with filter. I will NOT paint that way again. If I ever paint with two-part paint systems again, I will have a full body suit and full respirator mask with separate oxygen source and complete skin coverage. ANYTHING LESS IS ASKING FOR PERMANENT DAMAGE. As I get older, I occasionally get wiser 😉

When I painted the R75/5, I got the smoke silver paint and proper primer to repaint the Ghost. And it’s time to strip the bike to the frame so I can powder coat it.  And, so, now that I was going to have it all apart, well, after 105,000 miles, there are other things to replace including the timing chain and associated parts, the clutch, oil pump cover gasket and rear main seal, and upgrades to the engine electrical components.  The suspension is also on the list to upgrade.

I’ll write-up the work as I complete it and post links to these in this section.

11-Engine

21-Clutch

34-Brakes

61-Electrical

Revisions

2019-02-06 Updated 2015-2016 Refresh section document links.
2023-12-22 Added Video section about rebuilding Bing CV carburetors.

 

32 thoughts on “1975 R75/6 Rebuild: Project Index

  1. Great work! And I love all the pictures that follow along with the text. One question. Not enough info on cleaning up the cast aluminum parts. I’ve found that to be a problem. You make it look really bright and new.

    I like running my R bike with the expanded battery box. What about a lift off seat post to make things easier in the future?

    • Hi Howard,

      Well, the aluminum cleaning started with “parts cleaner in a can” for small stuff, or spay on engine cleaner. Next, tooth brush or brass wire brush to loosen any crud. Rinse and then wire wheel using a fine wire. Then, AutoSol aluminum cleaner – brass wire brush or tooth brush. Then AutoSol aluminum cleaner with steel wool if it still looked pretty dull.

      To polish, I used AutoSol “metal polish” (liquid) for cast aluminum. For polished aluminum, I used AutoSol aluminum polish(paste). I finshed off with AutoSol aluminum protective coating (spray), and then very light hand buffing.

      I decided to go back to the stock battery box as I had used a lawn tractor battery for many years which was a bit wider than the stock box. I’d cut the sides off the stock box so the tractor battery would fit.

      I’m not sure what “lift off seat post” is? Maybe you can explain that.

      Thanks for dropping by and looking at the project. I’ll be posting the painting content very soon (just finished sanding out the clear coat) 🙂

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  3. I have a 1975 r/75. I’m interested in restoring it as you did. What did this restoration end up costing you. Thanks for all the great info.

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    • Hi Jim,

      Thank you. I hope it looks as nice the second time I try to paint it smoke/silver. I am hoping to finish priming all the parts this weekend.

      Best.
      Brook.

  7. Thanks for the inspiration. I am currently doing a 75/5 and use your site for reference on many things .
    Thank once again
    Keith

    • Hi Keith,

      Well, cool beans. I’m glad you have taken the plunge with the goal of getting another airhead out and about. And, thanks for the kind words.

      Best.
      Brook.

  8. BeeeUtifull bike! As like you, I opt to paint for myself, rather than shipping it out. Never asked what the cost would be…when I picked it up (front fender and tank) I paid $500 and (acted) like I was thrilled. DID look good. First time I spilled a bit of gas, when filling, it streaked, With a good bit of polishing I finally got it to looking pretty good again. I was at Western Sizzling in Norman one day (had several passengers so I could not wait to talk to the riders) and I saw four VERY interesting BMW air heads. They had removed the batteries and boxes (put the batteries in saddlebags) Two had two barrel Hollys, one had a four barrel Holly, and one had some sort of electric super charger on a two barrel carb (in the original battery space. I have never been able to find such accessories. I made up some molds, but have not attempted to pour up a manifold for a two barrel Holly I have. I was sure wondering just how these performed! I THINK I may have been able to figure out my problem with getting my sliders off…any way, I will wait til tomorrow to start on it again.

  9. Hi,just want to thank-you for your posts.The high level of documentation,photos,and videos has helped me considerably. The project I’m working on is a ’76 R75/6 that I sold 25 yrs. ago,I was the second owner,and less than 1500 miles were put on in that time. Mechanically I’m comfortable working on it, but wiring has always been a bit of a mystery. Your step by step approach to a problem,as in your neutral switch,diode,clutch switch vid was the kind of process I needed to incorporate. Again, Thanks so much,looking for more. Don C

    • Hi Don,

      Thank you for your kind words. It was my hope when I started publishing documentation of my projects that it would remove some of the mystery about how things go together and how they work. It’s been my experience that fear of failure is the strongest force that prevents us from doing more work on our airhead bikes. Seeing what someone did, and having a recipe for doing it, goes a long way to replace fear with sufficient cautious optimism to get started.

      Best.
      Brook.

  10. Hi Brook – I am restoring an r90s and have an electrical question – I am not completely done hooking up the wiring harness (haven’t wired up the tail light, rear turn signals, horn, master cylinder), but being over-anxious, I hooked up a battery to see if what was hooked up would work – and nothing happened. I am hoping this is because I don’t have everything wired up and it’s not “completing the circuit” yet. Does that make sense?
    Thanks for your inspiring blog,
    Jon

    • Hi Jon,

      Well, I don’t have too many details of what’s connected and what’s not. If the ignition switch is connected and you turned the key, then whatever wire’s are connected MAY get power, but not if a ground path back to the (-) battery terminal doesn’t exist. Some ground paths are via ground wires (BROWN) others are via the mechanical connection between the component and the frame, engine or transmission.

      If you have any shorts, then you will blow a fuse immediately and nothing fused works. So, check the 2 fuses to see if either of them are blown.

      Anyway, use a volt/ohm meter to check the wires starting from the battery (+) to see if you read 12.6 volts. Work your way to the ignition switch and then work your way from it to the fuse block in the headlight shell. Then check the all the wires you have connected for power. Eventually, you will find the problem(s).

      Use your wiring diagram to help identify all the wires you have installed and identify the ground path for each.

      I hope that helps.

      Best.
      Brook.

      • Thanks so much, Brook – I did hook up everything today (all lights etc) and have NO power going anywhere. Battery is new (reads 12.7v), starter motor turns when I cross the solenoid screws….wondering if it could be a funky starter relay or diode board. Could I try running a wire from the battery (+) directly to the red wire on the ignition switch in the headlight shell and see what happens, or am I missing something that will short it all out if I try that?? Also, is it an issue if there’s paint between the coil brackets and the frame (lack of contact)? i’m not very experienced with the electrics, but am trying to learn and am studying your schematics…

      • Sorry to bombard you with replies, but…Success! I followed your schematic that isolated the ignition circuit, saw how to bypass the starter relay, ran a wire and everything lit up/worked. (even the clock, which I had hooked up to a battery in the winter and thought it was dead. I even took it apart to have a look inside…maybe needed a ground?) I was thinking last night that maybe when I was cleaning the starter plug taps with a wire brush on the grinder last winter, it jogged something loose….So Thanks again! – now on to the hydraulic brakes (which is also new to me).

        • Hi Jon,

          Cool beans. I’m glad you found the problem. The starter relay has an internal jumper wire between the two external (30) terminals that carries all the power for the bike. It can break. I suspect the rough treatment of the terminals when you used a wire wheel to clean them could have broken that connection.

          I wish you success on your project to bring an iconic R90S back on the road.

          Best.
          Brook.

  11. Hello Brook, I noticed a small leak at the bottom of the forks after having done a complete rebuild. I tightened the bolt at the bottom of the damper rods and …over tightened it. Desaster! I’m afraid I have to replace that rod. Any thoughts? Thanks. Chris

    • Hi Chris,

      I’m sorry to hear about your problem.

      There is a copper washer at the end of the rod that is supposed to provide a seal. Also, are you sure the leak came from the damper rod, or was it from the large plug that has the hole for the damper rod? That plug can leak too. I use Hylomar on the threads of the large plug to ensure a seal.

      I hope this helps.

      Best.
      Brook.

  12. Brook, I recently discovered the stud on the rear drive that mounts the bottom of the right rear shock is stripped. When I looked for the part number on BMW fiche, I couldn’t find it? Do you know where I can find the specs for that stud and where I get one?
    Thanks
    Mike

  13. Hi Brook, bike looks great. I had a very early 75/6 with R90s fairing, but left it the standard blue. I now have an R100GS and R100RS. Airheads just seem to get under your skin!
    I also paint a lot of my bikes and note that you use washing up liquid to clean off residue. Can I ask if you use pre-wipe fluid prior to painting and where necessary a tack rag?
    Your paint incompatibility issue might be contamination of the paint surface prior to painting.
    I confess to once using petrol as a pre-wipe on a frame job and you could wipe that finish off just by looking at it!
    Regards, Steve (UK)

    • Hi Steve,

      I did use pre-wipe prior to the paint work. The problem with the original paint work was I failed to use the proper primer for the paint. The solvent in the paint dissolved the primer. I repainted the bike a couple years later with the primer and paint from the same manufacturer, Glassurit.

      Best.
      Brook.

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