when I got it the plug wire was off and the throttle was stuck wide open …...looking through exhaust port the piston looks pretty scored and the rings appear to be stuck , Im hoping a piston will fix it I found a new old stock piston with rings ill know more next time I get to work on it when piston gets here , I really appreciate your help Steve- thanks a bunch by the way I have a retired logger friend who told me he has 2 NIB pro 800s? and when our local MCculloch dealer closed in 97? he bought 1k worth of parts -he said he never ran anything but macs & never would hes not doing too good hes 84 - I need to go see him soon -really neet man