Chainsaw Repair

The cast muffler says “CAT” in the part number on top. There may be the “jungle” style muffler which just has an exit port in the front corner and what looks like a small pipe. There was also a high flow muffler used on later saws with a larger discharge port.

The piston looks fine. Still has machine marks on it. If the ring gap is getting out of spec you could re ring it, but I would just use the ring you have if it isn’t heavily worn.

With ethanol fuel, the rubber seals on the bearings start to get hard and leak. If you’re suspecting an air leak, I’d check the bearing seals.