Piston wrist pin too small???
 

I just install a 61mm bbk and I think I install my 150cc wrist pin instead of the pin that came with the kit by accident. After I test drove it oil started leaking everywhere and engine cut off. Scooter would not crank up. Do you think a too small of a wrist pin could cause any problems??

If you put the wrong wrist pin it, a few things can go wrong.

1: The pin can shift to one side and break out of the piston
2: If it louse it can beat up the inside of the piston and then break loose from the rod.
3: It can cause the piston to tilt and seize up in the cylinder

Thanks. You were rightt. I took the engine apart and the piston had bad scuff marks on it and the rings were smashed! Now in see why i wasn't getting compression. Loos like I can just order a new piston and I'll b good. I saw one on ebay for $ only $14 61mm