seat rebuild and other updates

So, It has been over a year since I made a progress update, but I have been making progress.  First there was the seat rebuild I mentioned last time.  The seat is a formed metal pan with shaped foam and a vinyl cover.  That cover and foam was just wrecked.

The seat pan had some rust holes around the edges and was difficult to decide what to do with the pan, do I buy a new one or try and salvage what I had.

What I did was get all of the foam, which was glued on the metal and turned to dust when I touched it, off and wire wheeled the remaining paint etc off.  I then got some real POR-15 rust coating paint and coated the pan.

Once the paint cured I got the new foam and seat cover mounted and the trim replaced.  I think the finish on this is, so far, what I am least happy with on the restoration.  At some point, I may get the whole thing professionally redone.  I guess I haven't captured any pictures of the finished seat yet, but you can kind of see it here along with much of my progress.

I knew I needed to replace the super old rubber brake lines that were cracked and stiff and probably 40 years old at least.  I found a place near work downtown and had new lines made for me.  I thought I would hook everything up and be good to go.  What I found was the caliper was leaking really bad, even after my rebuild.  Rather than trying to rebuild again, I decided it was time to throw some more money at this and not be so cheap.  I bought a new, fully assembled, brake caliper for about $80 and slapped it on and success!  Well, kind of.  Now it wouldn't build pressure on the handle.  I poked at it for a few days trying a vacuum bleeder and other little trips to get the system bled.  No luck, so, out came my wallet again and another $70 for a brand new reproduction master cylinder.  The bonus here was, my grandfather had replaced the master cylinder years ago with a random other model until that was near impossible to identify and get a rebuild kit for.  What I bought was a reproduction of the original style master cylinder for a more original look.

Now my brake system is working, I just had to replace everything.  My most recent work is trying to get it started.  After rewiring the bike I was getting no spark.  After a week of so of scratching my head, I figured out the kill switch was bad, so again, rather then spending a bunch more time trying to rebuild the switch, I spent $40 to get another nice reproduction.  After that I was getting spark on one side only, better then nothing I guess.  Well today, I figured it out.  Traced it to the points and cleaned one set and re-gaped and BOOM!  two sparks!  So I buttoned up the electrical covers on the engine and started looking into the last few electrical issues on lights to work towards the startup.  I need to figure out why the tail light and turn signals are not working.  I hope to have those solved soon and ready to start.  Today I also manually tested and primed the oil pump for the two stroke oil.  I am committed to starting this soon and riding it this year!  I even bolted the license plate on today, I hop I didn't jinx it. 

Update

I haven't updated in a while due to us moving and all of the work that went into that.  I have still made progress on the bike though.

Tank Emblems

Here is what I was starting with, there was almost no paint left on these.  Originally these were chromed metal badges that were painted in most places.

They do make reproduction badges, but they are close to $100 a set so I thought I could refinish what I had.  I soda blasted the badges and masked the raised letters for painting to do the white and then re-masked for the black inlay and painted that.  I think some of the problem with the missing paint stems from them being on the gas tank and getting splashed with gas from time to time.  To try and help this I also applied some engine clear coat and baked the emblems to get it set.  I did find that baking the clear coat like you are supposed to did cause a slight yellow tint, but its hardly noticeable.  Here is the finished product.

Here it is on the cleaned up tank.

I thought I was going to have to repaint the tank, but when I cleaned it up and polished the paint it looked pretty good.  There was just a scratch in the decal on one side so at some point I may replace the decals.  So here is the reassembly so far.

I also managed to redo the seat which was much more damaged than I originally thought, I will do that update soon.  Once it warms up here I will work on the last few things and try and crank it up for the first time.

Assembly (cont.)

I have been making steady progress on assembly.  I got the cables hooked up asnd the enginecase put back on with new oil lines.  I fitted the carburetors and spent a lot of time pulling the baffles from the exhaust and cleaning up all of the burnt oil and carbon.  Next up is cleaning up the tank and redoing the faded emblems.

Big Update

So I haven't been updating my progress great, so here is a big update on what I have be doing and where I am at on the project now.

The Frame

After finally getting everything pulled off the frame I spent several days stripping the remaining paint and rust with a wire wheel.  Here it is all stripped and masked for painting.

I painted it with the same chassis paint as the rest of the black parts and gave it two good coats.

I managed to break off only one bolt when taking the whole bike apart, the problem was it broke off in the frame.  So, I had to drill it out and tap it with a heilicoil.

With that done, I could get started on reassembly.  

Wheels

Before assembly I wanted to get the wheels redone, they were in a pretty sorry state.

I was able to clean up the rims with some steel wool and polish.  The hubs took quite a bit of cleaning and polishing to get the aluminum shiny.  Once that was done I went ahead and replaced the wheel bearings while I was there.

The spokes were a bit of a challenge, the old ones were zinc plated and in a pretty sorry state.  I got them all off and managed to order a set of stainless steel reproductions from HVC cycle.  I was hesitant to try and re-lace the wheel and true them, it is notoriously finicky.  After a couple of tries though, I was able to get them laced and trued within spec.  Here is a shot of my truing stand with the dial gauge for checking the hop on the rim.

 

With this done, I could install the tires and tubes and start assembling.

Assembly

I managed to assemble the front end, fenders (after visiting the salvage yard for a new one) and some of the bolt on frame parts.

Once I got that together I could finally get the engine back in place, now it is starting to look like a motorcycle!

Brake caliper rebuild

This seemed like such an easy task before I started it.  I wanted to go through the front brake caliper and make sure that everything inside was good to go. Well I split the caliper into halves and took a look under the brake pads which looked nearly new.  Underneath was a different story, RUST, so much rust.  See brake fluid is hygroscopic, meaning that when exposed to the moisture in air it pics up water and the water then causes the system to rust from the inside out.  Couple this with sitting for several years and you get brake pistons that look like this.

To get to this stage, I had to free the pistons from the caliper body which took reattaching the master cylinder to the caliper and refilling the system with brake fluid and putting pressure on the pistons which helped me get them unfrozen but not all the way out.  For that I had to stick an air hose in each side and blow compressed air in while trying to keep from blowing the piston into my face.  This was not easy.  Once I got the pistons out I inspected the rubber seals and the pistons and found that there was no way I was going to be able to reuse these again.  I was lucky to find a company that manufactures stainless steel pistons for the caliper at $80 a pair, which isn't great, but helps me feel better about the stopping on the bike (when I first test rode the bike the front brake wasn't working at all, which was interesting to say the least).

After getting all of the parts in I cleaned all of the rust out of the caliper body and bore and worked on changing the rubber seals.

Then the final challenge was getting the pistons back in with the new seals.  The tolerance is so small on these that this was no small order.  I manged to get both of then partially in, but had to use a c clamp to get them the rest of the way seated.  Then fully assembled final product:

I didn't paint this part like all of the others for a few reason, first there wasn't a lot of rust on the outside and for the most part it looks pretty good.  That plus the fact that brake calipers need special paint due to the high temperatures and corrosive brake fluid, I thought it best to leave it and see how it looks on the finished bike before bothering to refinish it.

Finishing the engine

Alright, it has been two months and I have been plugging away at the engine that whole time when I got a chance.  It was a long process that was really helped by a great step by step procedure someone in the UK had documented (link).

We left off after having redone the jugs and heads, after this it was on to the main case and separating and cleaning it up.

Undoing all of the very rusted case bolts, I had to smack it good a few times with a mallet to separate it.

Inside you can see the crank up front and the two transmission shafts in the back.  I pulled out my caliper and measured the crank play and everything was in spec.  I pulled everything from the two case halves and tagged and bagged it.  Now it was time to get down to cleaning the cases.

Now case cleaning was a pain...in...the...ass.  The top half was pretty straight forward, some degreaser and scotchbrite pads got me a pretty good looking result.  The bottom half was heavily oxidized and super dinged up.  The front portion of the lower half is covered in aluminum cooling fins and my grandfather really only rode his bike around on the dirt roads near our farm.  This means that rocks that were run over by the front tires were picked up and thrown at the underside of the engine.  I cleaned and cleaned with degreaser and scotchbrite, hit it with the soda blaster, and event resorted to using a small screwdriver and mineral spirits on a rag trying to scrape and dissolve the worst of it.  Here are my results, not concours quality, but pretty damn good.

So having gone through the struggle of cleaning up all of the parts it was time to start reassembly of the engine.  Through this process I learned pretty much how everything on the motorcycle worked including the gearbox, which was the most interesting part and where the rebuild begins.

First thing we do is install the selector drum and the selector forks.

Then we install the inter meshing transmission gears.

Now we install the crankshaft.  Throughout this process I am replacing all of the rubber seals in the engine.  With a two stroke engine the portion of the case around the crank must be air tight since the fuel oil mix move both above and below the pistons to assure the lubrication, if you have an air leak the fuel mix will lean out and then you will start melting holes in pistons or seize the engine.  This is why I tore apart a working engine, this way I know everything is up to spec.  The next step is applying special RTV sealant to the bottom half of the case everywhere it meets the top case and dropping the top half on the bottom half and tightening the bolts.

Tada!  Now I reinstalled the array of gears, the rebuilt clutch, and the rest of the inner workings that mount to each side of the sealed up case.  Then we get to add our shiny restored covers.

Then we install the cleaned up jugs and heads.

I need to hit the sides of those heads with some more aluminum polish and a buffing wheel, but lets remind ourselves how far we have come.

Now the last step is to make sure all of those new seals and the case sealer I used sealed up our crankcase.  Now they sell a special leak down tester for two stroke engines, it costs, wait for it, $250!  Now this tester just comes with two things to plug up the two exhaust ports and two other things that plug the intake and allows you to pump it up and measure the pressure.  I decided to do this for under $20, with some PVC ends that I RTV sealed a tire valve and a pressure gauge from a farm sprayer, to plug the exhaust I bought some freeze plugs from the auto parts store and I pressurized the engine with 5 psi from a bicycle pump.

I had some air leaks around the rubber intake boots (where it meets the reed cage), I applied some left over engine sealer from the cases and let it harden and the pressure gauge above shows my results.  A near perfect seal, I held 5 psi with almost no fluctuation for 6 minutes!

I did rebuild the clutch while I was at it and found the first thing that needed wear based replacment, clutch springs.  I will order a set with my next bulk order from Economy Cycle.  I did end up replacing the clutch friction discs since one was cracked when I opened it up (I might have broke it trying to get it out).

Next up will either be the front brake or the frame.

  

Breaking the engine open

It could be put off no longer, it was time to dig into the engine.  I am using the factory service manual to disassemble the engine in the best order.  First up comes the heads and cylinders which are the last remaining engine components that need painting, the main case is supposed to be bare aluminum.  The state of the head and cylinders was rather poor, most of the paint was gone and there were old mud wasp nests between half of the cooling fins.

The first step was scrubbing 30 years of dirt and wasp nest off of everything.  I washed them with warm water and a stiff brush, which cleaned up everything and then took heavy cleaner/degreaser and q-tips and cleaned all of the dirt and oil out of all of the small crevices in the cooling fins.  Once that was done I used the soda blaster to strip the remaining paint and oxidation and went through the same hand cleaning process again to make sure everything was clean.  I then carefully masked off all of the opening and hit everything with 3 coats of high temperature engine paint.  Now as you can see below the edges of all of the fins are bare metal and semi polished, this proved to be a bit of a headache as there is no good way to mask that edge as the edge is no longer square.  I ended up painting it and the scraping and using a scotch pad to polish the edges.  Now scotch pads release small particles of aluminum abrasive, small enough to hide in engines and large enough to ruin bearings, so I had to make sure the masking was still good and wash everything a third time to get rid of the sanding dust, but they turned out pretty good in the end.

Next up is Clutch and engine gear disassembly and inspection.