I used a crankshaft with a stroke of 39.7 and it fit in and the flywheel bolted on in the correct place, all I had to do was bore out the bearing holes from. 875 to .9055 ,23mm, and install new needle bearings. Used the same thrust washer and got new seals. Didn't have to make the crankshaft, lots of work doing that and the rod hooked up to the piston. Easy easy. Bore 56mm. You can get a 58mm cylinder for 105cc
Wow now I know where to send my next 3400 build for a 98cc saw. Some impressive work there Todd and if you decline I will keep using the like button too.