Yamaha ebike motor: Chain seems to skip on the forward sprocket.


New member
Local time
12:21 PM
Apr 17, 2024
Mission Viejo, CA USA
We bought an MBK (Motobecane) ebike for my wife. It has a Yamaha motor on it. It's European spec, so PAS only. Whenever I start pedaling on it, it seems like the chain is slipping off the motor sprocket for maybe a half turn of the crank, and then the motor kicks in and it smooths out. Every time I coast a bit and then start pedaling, it does this, making an awful noise. Has anyone encountered this? I'm thinking it might a problem with the torque sensor?
Full disclosure: we bought it at a discount house, so no warrantee. It was a new bike, but perhaps it ended up there because of this problem.