Need Help 01 KX65

[hp500efi]

My 10 YO was running his KX65 pretty hard down some gravel roads with us when the machine just died. We were running late that day and since we could not get it started, we parked it and later came and got it.

Upon getting it, it started hard, but started. I immediately noticed an internal friction noise so decided to stop it. Checked the normal, compression good, fuel good, clutch good, will run in eavry gear but the internal friction noise is still apparent and noticable has an affect on the smoothness of the motor.

I am thinking that he blew out the crank but need to know what I should do from here to determine that. I have always wrenched on the bikes but never something like this. I did read that some of the KX65 cranks were failing and wondered what the symptoms were of a bad crank.

Can I remove the left hand side cover plate and determine if the crank is my problem. How difficult is changing a crank?

Thanks for your help..my Son is bugging me to get it running. In the meantime, he is riding my other Son's XR80 and he is getting bored :)

 

[95KDXer]

The KX65 is rough on cranks. You need to remove the cylinder to get to the rod, if the rod has up and down play your bottom crank brearings are toast. You need to install a new crank assembly Wiseco makes an aftermarket that is little less expensive.

 

[Jasle]

you can checkt he crank bearings by removing the side cover and seeing how much play the end of the crank has. These are not the bearings that usually go out though. The problem bearings are the rod bearings. You'd need to take the top end off and see how much free play there is in the rod. My guess is its toast. the wiseco hot rod kit is the way to go.