I ordered a piston and cylinder for my Flying horse 66/88 cc motor. The wrist pin hole in the piston is too high and the piston hit the crank, locking up the motor. I shaved 3/16 off the bottom to get it free but now the engine has no power. How do I make sure I order the correct piston and don't end up with the same one? What engine would have the same diameter piston but a different pin location? Thank you