I never did a project thread for my cb500 so I feel like I should do one for this bike. I took pictures of the cb500 but dumping all of the pictures after you're finished just isn't as good as updates as you move along.
Here is a 1965 honda S90 that I paid $280 for which is too much considering all that is usable is the frame, tank, seat and muffler. From what I can tell, it sat outside for many years, because there were pine needles in the gas tank and intake, and about 20 nuts fell out of the battery area/above the engine. The person I bought it from had freed up the engine and bought a new piston and a used jug for it. Problem is the someone had taken out one of the valves and valve guide, then damaged where the valve guide goes. The other valve was rusted shut and I'm sure I probably destroyed the guide with all the rust on the valve. This, along with a missing carb, exhaust header, and some of the internals of the engine being rusty is why I decided to go with a yx140cc engine.
The bike is mostly stripped down to the frame save the swing arm and some other stuff. I don't plan on repainting so I guess I am going for the "patina" look.
Here are the things I have done so far:
- Cleaned the gas tank and sealed with por15, but there are some light spots so I will do another coat soon
- Taken the forks apart, decided they were too far gone, and bought a set off ebay and rebuilt those
- Got the wheels disassembled, removed the rear bearings because they were rusted shut, bought new rims from dss, and got the front laced with new spokes. The rear brake was completely seized, so I am going to see if a machine shop can turn down the rear hub so I have brakes again.
- I took the head off the yx140, sanded the combustion chamber a bit, tried to match up the intake and the port, probably didn't do very much, but hey probably didn't make it worse. I also installed a z40 cam with stronger springs as well.
- Bought various parts from ebay and other sites for things that were missing or broken.
This is our storage locker, I bought the bike back in the winter, but didn't have any room in the garage at the time so it went here.
I don't have any pictures of the pine needles but here is what the petcock looked like.
This is the damage to the original engine.
Old forks, the top of one of the forks is all messed up. There was a monstrosity of a bolt with 6 washers in it because the stock bolt wouldn't fit because of the messed up threads.
New to me ebay forks after being rebuilt. I also got new fork ears for the headlight bucket because one of the tabs was completely snapped off. The s90's are very strange, the forks that came with the bike had a screw off collar to hold the seal and tube in, whereas the ebay ones are probably from a later year where they went to snap ring style.
The steering bearings were surprisingly clean so someone in the past must have actually done some maintenance. I can't put it back together yet because one of the steering limit stoppers on the lower triple is broken off so I need to get a bit of metal welded in its place.
I probably could have reused the rims but I made that mistake with my cb500 so I bought new rims from dss. $100 for front and rear delivered. The rear wheel on my cb500 had a bit of a flat spot so even after attempts of truing it there is still an up and down wobble. The rear brake was completely stuck so it took a hammer and a screwdriver through the holes in the hub to get it free. As you can see the bearings are shot, but they came out surprisingly easy. Nothing holding them in either, they just sit there.
New sprockets front and rear, and a new chain in the mail.
The glass was broken long ago on the speedo so I bought a used one on ebay.
For the new engine, it is a piranha 140cc (yx140cc) I got from tbolt usa, along with a z40 cam and a vm26 carb. I sanded the combustion chamber but probably didn't really do much. I smoothed out the carb to intake boot so it flows better but I don't have a picture right now. I also tried to smooth out the intake port but it is pretty small so instead I just did the part close to the intake and not near the valve guide. I don't have after pictures but I have before pictures. Tomorrow I'll add after pictures.
Next is to get the rear hub turned so the face is flat and not rusty. Also I am trying to work out what is the best way to mount the engine, because it doesn't line up with the stock holes, and I will need to find someone to make me an exhaust header to hook up to the stock muffler which is in good shape.
