Cylinder Base Gasket for Husqvarna 550XP Mark II

This Husqvarna 550XP Mark II base gasket seals the cylinder to the crankcase. Any time the cylinder comes off for a piston, ring, or top-end job, a new base gasket goes back on.

Why a new gasket matters

A two-stroke engine depends on a sealed crankcase. If the base gasket leaks, the saw pulls in extra air, runs lean, and can seize. Gaskets compress once and should not be reused, even if they look fine.

Order it with the rest of your top-end parts. See our power equipment parts for more 550XP parts.

On the 550XP Mark II, a top-end job usually follows a seizure from running lean or with old fuel, so fix the root cause as well. Check the intake boot, impulse line, and filter before reassembly.

Install notes

Clean both mating surfaces without gouging them, and set the gasket dry unless the service manual says otherwise. Torque cylinder bolts to spec in the correct pattern.

After a top-end job, a pressure and vacuum test is the best way to confirm the seal before the saw goes back to work.

Keep spare gaskets in the shop if you run several 550XP Mark II saws. Small parts like this are easy to forget until the saw is in pieces on the bench. Confirm the part number for your serial range, because a gasket that is almost right can still leak. Torque values and bolt patterns are in the Husqvarna workshop manual for the saw.