While riding my raptor a while back fairly hard along a beach she started to vibrate. I shut her down and towed her back to camp, upon furthur investigation I found the upper engine mount broken so I had that replaced and things were better but not right. After checking oneway,flywheel etc everthing there was ok so I checked for broken rocker on the top end and that was all good. Lastly I decided to check the clutch and this is where I found the counter balancer key broken and the nut loose, has anyone heard of this before? Glad I found something wrong, not a good feeling having the rappy go down again[img]i/expressions/face-icon-small-sad.gif[/img]

 

I have not had this problem on my raptor but had this problem on one of my boat motors I talked with a old timer and he told me that the key way is only there to keep the flywheel or in your case counterbalancer in alignment. I am assuming it is a tapered shaft if it is you need to clean it up very well and use lapping compound on the counterballancer and the shaft at the same time use cource then use fine until the shaft is polished and the counterbalancer is polished tobether this will enshure that they are mating 100 percent then clean them both with acetone or a carb cleaner and replace key way and you should not have anymore problems with it moving or coming loose and breaking your keyway.
Hope this helps you avoid any more problems.

 

Thanks for the reply, good advice, I am getting a new nut and key as we speak. I will clean up the surfaces and then loctite just to be safe. Not sure if the fella who assembled my bottom end left the nut loose or if there is another reason the nut come loose[img]i/expressions/face-icon-small-confused.gif[/img]

Gav

 

There should be a locking tab washer on that nut (the ones you bend up against one of the flat sides of the nut). And they should never be used twice, always replace them if you need to take off the nut.