Building an engine & a bike from random parts - 1979 - 1981

Is it possible that a previous owner has bolted the final drive to the other side of the swinging arm without the spacer shim and then tried to compensate by enlarging that hole?

One of the possibilities as well. Nothing surprises me. Poor bearings... It does look like nice almost machined. In the back of my head it was kind of puzzling me because it would take quite a lot of grinding for the shaft to shape it like this. And what about the shaft? It would grind itself to oblivion.

Looong time!

Not that nothing has happened in the meantime, but... There were hundreds of steps. Literally, without shortcuts. Not out of the woods yet, but starting with a handful of bolts and a spare cylinder block with a damaged sleeve it's not been exactly a head start.

Well, I haven't been pushing it, and it would actually be quite easy having all the resources.. Cut the hight tech talk! Following basic engineering and mechanical principles, it's all about math and formulas and a skill focused on being detail oriented . Not that I'm an expert, but I've learnt to be this way.

Just a photo of where I am right now with this totally random engine. Based on my 'workshop' limitations, it will be mostly a 1979-80 A1-A2. Crankcase is 1980, and some other parts 1981. I was going to convert it to a full 81 or even 82, but I am missing parts, so I need to settle and compromise. Like the ZN connecting rods for example, and such.

The biggest obstacle in such build are the electronic parts. They are insanely expensive, even more so aftermarket! So, I fell back on the A1-A2 that I had.

For now, as a teaser - the left side (assembled but not 100% done yet, missing the LHT bolt)

Look'n pretty nice Stan.

Truly inspiring Stan. It's amazing what you can do with 40 year old spare parts gathered from everywhere. That lump will be the show piece of the next bike. Kudos !!

I truly admire your achievements, Stan. The parts are always finished to such a high standard. All the more impressive considering your lack of proper workshop facilities.
Regarding that left hand thread bolt, have you considered having one made?