xr50 rebuild

[slaughtermx]

I'm rebuilding my xr 50 top end and I don't have the sservice manual. How do you loosen the timing chain in order to get it off the cam and pull the head off?

 

[JuliusPleaser]

There are three bolts on the cam sprocket. Remove them and the cam will fall off, and so will the chain.

First you'll have to remove the round cam cover. There's a 10mm bolt on the right side of the head that retains the cover. That's right. . .the bolt goes alll the way through the head.

 

[91-YZ250-Chris]

yes remove the bolt on the other side of the cover first, then just remove the 3 bolts on the cam sprocket and then just pull it off. you should really get a book because you are going to need the torque specs for the motor, i have rebuilt this same motor several times and the manual really helped out but be sure to post a question here if you are unsure before you go ahead with it

 

[wasted]

theres also a camchain tensioner in the bottom end and a tensioner bolt on the underside of the motor...

a manual helps, but those little motors are so simple and straight forward that you really dont need one, just pay attention to what your doing while taking it apart...

I had never had one apart before and I tore my nefews CRF50 completely apart, replaced the crank, and completely rebuilt the top end in just an afternoons time, all without a manual and with absolutely no problems, there isnt much to them...

one thing you should do is make sure you know where the timing marks are in relation to each other and the marks on the motor so you can retime it easily if/when things get moved while rebuilding it...