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.

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 Silver Ghost – Starting a Restoration

Silver 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 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 !!!!

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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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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.