I just picked up a SXL-925 cheap on ebay. The saw has good cosmetics but very low compression. (50 lbs plus or minuts) I havent been into the saw but what would the probable cause of this low number be? Are ne jugs and pistons available? Im new to the old saw hobby and to this site but Ive got the fever bad. This is my thirds 925..got the other two runnin good. THANKS