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!