A 48mm pop-up piston for the Husqvarna 262XP chainsaw. It fits where standard piston 503531171 does; the 261 takes a different piston. The raised dome reduces combustion chamber volume, which raises compression, tightens squish and helps low-speed torque and starting; it is not a guaranteed gain in top-end power, and for a straight repair the standard piston is the right part. Cylinders vary, so check piston-to-head clearance with a solder test and choose base gasket thickness from what you measure. Set the high-speed mixture slightly rich, use fresh high-octane fuel and take the first tank gently.
- 48MM POP-UP PISTON - A raised-dome piston for the 262XP.
- FITS HUSQVARNA 262XP - The 48mm saw. It fits where standard piston 503531171 does. The 261 takes a different piston.
- WHAT A POP-UP DOES - The dome reduces combustion chamber volume, which raises compression, tightens squish and helps low-speed torque and starting. It is not a guaranteed gain in top-end power; for a straight repair the standard piston is the right part.
- MEASURE SQUISH ON ASSEMBLY - Cylinders vary, so check piston-to-head clearance with a solder test through the plug hole and pick base gasket thickness from what you measure. Too tight and the dome contacts the head.
- SET IT UP RIGHT - Higher compression runs hotter: set the high-speed mixture slightly rich, use fresh high-octane fuel and fresh oil, and take the first tank gently.