Vintage Motorcycle Eccentrics

Just some better detail.

I have the cases together. One picture shows the middle of applying some Hylomar, I finished, smoothed and thinned- so just a smear. Especially wanted to make sure crank area was well sealed.

I did goof up and forgot to put a circlip in the proper order on the shifter. But only took a few extra minutes. It keep the shift shaft from pushing into the case.

The only thing I’ve had problems finding is the wrist pin bearing and pin. I think I have one that will work coming- but will have to wait to make sure. Might have to take a couple mm off the pin lenght.

I'm still very impressed with the mass in those cases. Much like the Aermacchi cases.

The 125 has the same cases (with slightly smaller cylinder stud spacing etc).
Pretty robust for not very high output engine.

I just put the clutch on- I have pushed the big spring down and gotten the nut to start before, but could not this time. So made up a plate that I could tighten down.

Still some polishing to do

Nice to be that close to the end of the engine build. Wish I was that close. I know you have a good buffer. I have a ton of buffing supplies left over from my business. Also several small scotchbrite wheels which are great for deburring steel parts.

I cleaned out the holes and installed studs. (Then got sidetracked into working on wiper for vaporhoner).

I used the Snap-on stud tool I got unused but second hand. A friend that does a LOT of OSSAs said these are the best.
It works really well.

Nice set. I assume they are metric threads, right?

John H wrote:Nice set. I assume they are metric threads, right?

Yes, Metric.
I damaged one original ‘die’ on a particularly stubborn stud. But I cleaned the taper back up on my little lathe successfully. I did get a replacement, but still using original one.

The ‘head’ will work with ‘standard’ thread, but of course need to buy appropriate ‘dies’ (or whatever they call them).

I fit piston/rings/cylinder.
I fit an aftermarket ignition/charging, so have to set timing. They give it in degrees or mm on the flywheel. Of course, the flywheel is a different size. I didn’t think to measure the rod length when apart- with that it is seconds with an online calculator.
I could fit my cam timing wheel- but that would sure take longer than a few seconds.

I suspect this engine is not very touchy on timing, it is fairly modest in output. But it would be nice to know and a lot easier to setup on the bench.
Guess it is time to fit the wheel. (I did transfer from the other flywheel by eye, and likely that is close enough).