Here’s a link to a short video of the startup of the Grey Ghost on Halloween night.

 [flickr video=5142011702]

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.

Lessons Learned

Before I started, a blog I read 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 were past their service life.  So he got both heads and I had him replace the seats, valve guides, springs and exhaust valves.  Randy does great work and is willing to share his knowledge. 

I priced out the carburetor repair and rebuilding, replacing the rear sub-frame since I knew it was cracked, 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 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 disapointment, 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 the 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 Brian 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.” 

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.

This evening, Halloween, I got the Grey 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.

 
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 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 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”

 
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 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. 

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.

 
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.

 
Bar End Mirrors.

So, a couple of “Before” and “After” pictures.

The Grey Ghost - Starting a Restoration

Grey Ghost - 1975 BMW R75/6 Buck Naked

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 Grey 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 Grey Ghost came back to life.

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

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 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 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.

 
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 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

 
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.

 
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.

 
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.

 
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 . 

 
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 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 …)

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 …

Over the 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.

Before.

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.

“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.  There is a mark on the piston top “VOR” that indicates the side of the piston facing forward.  Be sure you have them aligned correctly when assembling on the connecting rod.

C-clip covering the cutout in the piston.

Wrist pin assembled onto Piston and connecting rod.

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

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 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, wiggle the cylinder a little so it covers that side of the ring then press the opposite side into the ring gap and wiggle the other side of the cylinder past a ring.  Easy and slow does it here.

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 – gasket covering push rod tube holes

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.

Inserted push rod.

Rocker arm assembly attached to cylinder studs.

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.

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 the top of the peddel casting so the peddle would move freely.

Right Side.

Front showing cross over pipe.

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.

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. 

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.

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.

Next, I took off the float bowl … and now you can see the Uglypart … 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.

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 which is very helpful.  I’ll refer to part numbers in this diagram in the following material.

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.

I found details in Snowbum’son-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.

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.

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

Then I assembled the housing putting 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 one side of the shaft.  This should be closer to right side on the right carburator. 

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

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).

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.  So, 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.

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 and 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.

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).

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 O-ring, but my handy Ace hardware had a metric replacement .  I put a tiny bit of antiseize on the jet threads as they are brass and screw into pot metal threads.   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.

I reassembled the slide (#13) with the new diaphram (#16) from the rebuild kit putting 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. 

Then, I put the top (#20) back on and put a tiny amount of antiseize on the four screws (#21) that secure it to the carb body. 

Now for the Good part.  Here are “before” and “after” pictures showing the rebuilt right side carb and the yet to be rebuilt left side carb.  Definitely night and day. 

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.

 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.

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.

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.

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.

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

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

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.

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 Grey Ghost is coming back together.

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.

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.

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.

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.

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.

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.

Here’s the Grey 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.

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.

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. 

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.

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”  

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

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

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.

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.

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.

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.