hey riders, I have A problem with my 66/80 cc raw motors engine, everything has been a nightmare. I bought the engine kit used in a box for 100$ and I have already put another 100$ into getting semi running on a bicycle. It wont run right at all... there is no power and when I have the engine engaged. When i pull the clutch the engine races. I have to keep trying to adjust the choke to even get it started, and I have to be pedaling atleast 15mph to get it started. Do i have a blown piston???... I have replace and adjusted the carb, the cdi the magneto... Im afraid of putting more money into it... dont know what to do? do you think it is forsure the piston... I mean what else could it be. please help me if you have had similar problems or understand the motor well. thanx happy trails