Brand new Hyway POP UP extra compression piston kit. Fits Stihl chainsaw models MS391, standard 49mm bore size.
The kit includes 49mm POP UP piston, rings, wrist pin, and circlips.
Do you want to add power to your saw without spending money on expensive porting? This POP UP extra compression piston from Hyway will generally add at least 10 psi compression over the stock design piston. More compression equals more power.
1 year warranty against defects on this Hyway piston kit.
Wolf Creek Saw Shop is a proud U.S. seller, we ship within 1 day of receiving payment, and you will get your parts quickly!