Rebuild questions: priming oil pump and cam chain replacement

I'm halfway through a top end rebuild of my XR600R, and, before I reassemble it, wanted to get some advice on oil pump priming and cam chain replacement.

First, since I have not had the bottom end apart, will I need to prime the oil pump? If so, how is it done; I have seen reference to taking the side case off and priming by hand, as well as kicking the bike to prime. Which is it? Do I have to disassemble the bottom end to prime the pump?

I have replaced pretty much everything in the top end, but just recently read about stretched timing chains. Is this something I should consider? How long do timing chains last? Do I have to get into the bottom end to replace it, or can I do it from up top?


I just rebuilt my 93 XR600 two weeks ago.

Concerning the oil pump I just pored the oil through the valve cover after every thing else was buttoned up and kicked the bike over a couple dozen times with out the spark plug and then started the bike and loussened the oil pipe to the head and checked for flow. As for the cam chain rotate the crank to TDC if the marks on the cam dont line up properly with the cylinder then the chain is the culprite, replacing the chain requires removing the clutch cover, clutch, impulse generator, and gears for same, (easy to do if you can rebuild an engine)

Thanks George. That's good to hear about priming the pump. I guess I have to wait until the head and cylinder are back from the machinist to test the cam chain. Thanks for the tips.

I did the same as George, I loosed the oil pipe at head w/o spark plug and kicked and kicked some more but couldn't get oil to come out. As soon as I started it oil came out immediatly, my guess is kicking just isn't fast enough to get the oil to flow all the way up. David

I finally got my parts and rebuilt the engine. It turns out I did have trouble getting the pump primed. I couldn't get oil up to the head by kicking or by starting it; waiting for oil after I started it was the longest 30+ seconds ever. I finally had to remove the clutch cover and run the pump by hand until I had oil flow. I had intended to pour oil into the pump to prime it, but didn't have a clutch holder tool to get the clutch off. Turning the oil pump by hand seemed to work; I have plenty of oil now. Hope this is helpful to someone.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now