The motor i bought has a bcc head on it. I put a stock carb on it that came with a different motor I had. It had no top end so I bought a red line performance carb with a reed set up that bolts up to the cylinder. Still does not have the RPM it should. So I bought a 2 window piston, since I had head off i changed head gasket from thicker copper gasket to a very thin head gasket, hoping it will have a little more compression still low RPM. I have a 42 tooth sprocket on bike. I am going to buy some 100 octain gas hope that does it. Any one have this problem or have any suggestions?? Before I buy a new motor can any one tell me witch one will work best with a cylinder and intake with reeds and an Oki carb I bought off internet, thought it would work on the long rod motor but it will not need short rod motor.am I wasting my money or should I just buy a Frankenstein motor????