Piston Slap

I Have A 1983 xr500r that tends to slap the cylinder when I am in a low rpm in 1st, 2nd, gear. The engine burns no oil, has great compression, and starts on the 1st kick. I am running a 14t front and 51t rear(came with the bike, and slightly worn) until I can scrape the cash for a new set of sprockets. I was wondering if the cylinder sleeve could be worn, or mabey the larger-than-stock, sproket on the rear is affecting the way the engine runs at lower rpm. I know that the xr500s have more midrange and top-end than the xr600s do, cuz I used to have a 1987 xr600r. I am thinking that the stock 48t rear will correct the problem. Any input would be appreciated!

Are you sure its piston slap, if you're not burning oil? I've never heard of slap on a tight motor. Could it be possible that what you're hearing is a worn cam chain?

My buddy, xrjohn, checked out the cam,cam journals, cam chain,and it was all in good condition. The main goal when we torn the motor down was to replace the the transmission gear set with the spare from my parts motor. (1st gear was missing a tooth) We cleaned all the smudge and debris from the inside of the cases,and assembled again only to find that oil was leaking form the warped clutch and alternator covers. xrjohn had the fix for that. He bought a 1/2" piece of plate glass and then glued coarse sandpaper to it. We sanded the sealingsurfaces until they were level. Presto! No more leaking oil! In answer to the question, No, I dont't think that cam chain is worn, as the cylinder head was in excellent condition. This motor had a bad tranny, so we figuerd that the motor didn't have a ton of miles on it. We didn't replace any engine parts except for the tranny. I will keep my fingers crossed and hope that the cam chain dosen't fail me. Thanks for the input.

-==1983 xr500r

--Plastic refinished with plastic renew-Looks brand new!!


--New seat cover

--Lots of power=Lots of FUN :)

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