Product Overview
Brand new Hyway 49mm cylinder with pop up high compression piston kit. Fits Stihl chainsaw model MS391, also fits MS311 as a big bore.
The kit includes Nikasil plated cylinder, pop up piston, Piston rings, wrist pin, circlips.
High quality kit that comes with a 1 year guarantee against manufacturer defects.
These pop up pistons are impressive and normally add at least 10 psi higher compression than the original style flat top pistons. More compression equals more power.
Please ensure you have the 3 bolt flange as pictured, there is also a 4 bolt version that is not compatible with this cylinder.
