Hi guys. I have a 86 Yamaha Moto 4 225 that I am restoring. Got it running but it has a jerk when you start and stop , when you shift gears, and when you let off the gas. The backlash is in the transmission. The u joint and rear end are good. Do these have a problem with the transmission ?

 

I have the same quad, and although mine doesn't have this problem, I am hoping you get an answer.

 

Thank You. I have the clutch and the rear end out so I can check the free play in the drive line of the motor. When I put it in gear and hold the drive shaft, the clutch shaft, will rotate back and forth about 1/2". that is where the play is coming from. I took the side plate off the transmission and checked the backlash in all the drive gears,and they are all good. So I would say there is something in the bottom of the motor not right. It does not make any noise ,except for a Jump and a Clunk when I work the throttle.

 

Did you ever figure out what was going on with your quad? I have the same thing...same problem. I have yet to tear into the bottom end of the engine but have pulled the rear swingarm/diff assembly. Spin the driveshaft in neutral and it seems fine. Put it in gear and spin the driveshaft and I get almost a 1/4 rotation before it grabs. I was hoping to just have to replace the u-joints but not the case. Let me know what you found, if anything. Thanks!