Let me preface this: there is not another thread on this subject already. I don’t wanna hear it.
I have a Sachs Westlake with a 504 engine. The crankshaft used to lock up on it and after many clutch rebuilds, I never did figure out why. Chalked it up to bad bearings.
So I rebuilt it with a 505 D shaft and a Derbi Motplat flywheel. Set the timing and bam fires right up, sounds great.
Only sometimes when pedal staring the bike, the pedals lock up. When you go to turn the flywheel, it moves, but comes to a dead stop in either direction after 90 ish degrees either way. Felt like a busted or stuck ring so i took the head off - everything looked great. Reduced the problem to the clutch.
Does anyone know what can make a Sachs clutch lock up? It’s assembled perfectly according to the manual. It has probably less than 0.5mm of play. The clutch hub (gear that all clutch components slide onto) looks a little worn, like it’s had a tough life. I can try to take a photo. I’m wondering if maybe the rotation is causing the metal clutch plates to bind up on the hub and restrict them from sliding in and out like they’re supposed to. What do you guys think? Is there a way to modify athe parts to reduce the chances of binding? Thank you.
AlSO: sometimes upon rebuilding the clutch, the bike starts but revs and the clutch does not engage the back wheel at all, further suggesting that the plates are bound up on the hub. Maybe I just need to buy a full clutch assembly. Does anyone have a decent one for sale?