Hey everyone i have a 99 Mxz 600 and for the past week it has been running bad. I have ran some methyl hydrate through the gas and cleaned the carbs and the RAVES and that didnt help. The problem is that it wont rev over 6000 rpm. It runs perfect untill you try to go over 6000 rpm then it sounds like it hits on one cyl. But if you hold it WOT for a bit it will sometimes rrev out to 8000 but now it wont anymore. I pulled off the head and the cylinders and the one piston (PTO side) had pits in the top of it just around the perimeter of the piston. So im gonna rebuild it withj new pistons, rings, wristpins and bearings. Will this solve the problems? or is it getting air into it from somewhere? Could it be the seal around the PTO??? any help would be great
How many miles on the sled, might be a good idea to pull the base out and replace the crank seals and check the crank bearings.Repack the bearings with isoflex grease. :undercover:
Where I sled: Gaylord, Indian River, Frederic, Grayling, Alanson, Mancelona, MI and N.E. to N.W. UP
Posts: 765
yeah those engines are known for the center crank seals going bad. I'd with 8000 miles it about time. I would do the bottom end also. The center crank seal went bad on mine to as well as many other things in the engine.
