XR650R Top End Rebuild??

I'm in the middle of rebuilding my top end on my 650R and was wondering about the o-rings on the top end. I've got my "complete" top end gasket kit and all it contains is the head and base gasket. I'm used to "complete" kits containing every gasket and o-ring on the entire top end. There is a small o-ring in the head and one bigger one at the bottom of the cylinder. Is everyone that's done a top end on these bikes just putting the old ones back (if they still look good)? I'm used to replacing everything just in case so I don't have to pull it apart again. Should I order some from Honda, or can these be re-used?

Also, how much side to side play should the rod have? Just to check, I grabbed the rod and wiggled it a little. There seems to be a few mm's play. Does this sound right?


Anybody? Someone has to have done their top end on this bike. I know they're reliable and all, but... The manual says replace the dowel pins and the bottom o-ring with new ones. My engine looked liked new when I took it apart. I have this weekend to put it together, or order the parts and wait another week???

I did the top end on mine, and I don't think I replaced thos little o-rings. I don't think there should be a few MM's of freeplay in your rod, though. I was able to move mine back and forth one, MAYBE two mm from one side to the other.

However, you should be okay. Just replace the main gaskets, and the valve guide seals, since those ALWAYS leak over time.

Thanks! Damn, I already got it together. Hopefully the valve guide seals will last a little longer. The engine had low miles. I only took the top-end off because I added a 680 kit.

Does this help?


Yeah, thanks! I had a friend come over with more experience with these. He measured it and said I was alright before I put the top end on.

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