so u think that those are good numbers? i thought they seemed kinda far apart. it probably wouldnt hurt to rebuild it next year would it? and that was a cold test. on the plugs what do u think is causing thoes two to be really black? i talked to my dad this morning and he said it sounds like it its getting oil fouled. he has never really looked at it and he doesnt know much about snowmobiles but he knows his engines.