A little problem. I have just re built the 250 engine 250cc. Txt pre pro.

New bore, piston, mains. Turns by hand beautiful. I have come to put the magneto flywheel on and it locks the engine up when you try and tighten the nut. It seems to be locking on the magneto internals. Without the coil inserts it tightens up. I don’t believe the crank can be miss aligned it is equal both sides and I’m sure the crank would not turn nice if so.

Any ideas please?

Bob

Hi Bob, it would appear that the magneto is coming up against the stator plate, therefore the crankshaft must be located too far to the right of the cases. This means the bearings may not be fully home, or the crankshaft may simply need to be centralised in between the cases.

Bye, PeterB.