As I bought two bikes, I got two engines to choose of. One bike was built in 1977 and one in 1978. The plan is in the end to have one running engine and a some spare parts. The 77 engine wasn’t running for more then a decade and the piston rings seems to be rusty – it’s not turning. The 78 engine has more KM on the speedo, better carburetors and a better cylinder head. The result are 10 more horse power on the paper. This engine started quite easily with the kickstarter and sound mechanically healthy.
The first thing which made me worried was, when I moved the engine out of the frame was the fact that there was almost no oil in. And there was a lonely washer ling in oilsump.
When I’ve put of the cylinder head, the first impression was surprisingly good. The camshaft looked alright, and all the valves are closing tightly. On the cylinder was still a bit of the cross grinding visible.
When I put of the cylinder, there was a whole different story told. The low oil level left his marks on the pistons. The pistons are the first oversize.
I brought the cylinder to a specialist and he was pretty confident, a new cross grind would do the job and the tolerances would still be small enough for new pistons of the first oversize.
On the next weekend I’ll get the cylinder. And then I got to do some decisions on which base (77 or 78) I’ll build up the engine. But that’s a whole new story …