Well I'm new here but excited to have found this site. We had a sound in the engine on one of my Blasters so we cut it off and towed it out of the woods. I tood the side cover off and found some old pieces of broken spring in with the gears and it looked like there was no damage done so I put it back together but went to crank it and it was like the motor was stuck. So I'm not used to working on these so much so I had my friend who is look at it. He took the top off the motor to check the piston. It was all in good shape only it would make almost one full rotation then stop. It seems like something in the bottom is stopping it. Only thing is when you take the ballancer gear off it will make the full rotation like nothing is wrong. Also the balancer will turn with no problem as long as it is not turning the crank gear. Why will it not make a full turn when they are together. We made sure the dots on both gears were lined up and everything. I hope someone has an easy fix for me.