Piston Kit 2-Stroke piston kits are gravity cast aluminum alloy (not forged) with 18% silicone content, which produces an extremely light but very strong piston. 4-Stroke pistons are forged from 2618 aluminum for superior strength and durability. 4-Stroke high-compression pistons improve power and torque across entire rpm range. 4-Stroke big-bore pistons increase engine's displacement, torque and peak horsepower. All pistons are heat treated with a T-5 hardening and tempering cycle. All pistons skirts are coated with a hi-tech molybdenum disulphide (MoS2) coating for faster break-in time and increased piston life.
Standard Bore 94.93mm, 12.5:1 Compression
2003YamahaWR450F
2004YamahaWR450F
2005YamahaWR450F
2006YamahaWR450F
2007YamahaWR450F
2008YamahaWR450F
2009YamahaWR450F
2011YamahaWR450F
2012YamahaWR450F
2013YamahaWR450F
2014YamahaWR450F
2003YamahaYZ450F
2004YamahaYZ450F
2005YamahaYZ450F
2006YamahaYZ450F
2007YamahaYZ450F
2008YamahaYZ450F
2009YamahaYZ450F
2010YamahaYZ450F
22915A