WSM Piston Kit - Yamaha - +1 mm 50-520-07PK

A piston kit is the heart of your engine's combustion cycle—when yours show wear, you lose compression, power, and efficiency. WSM's +1mm oversized pistons are engineered to restore your engine to peak performance while exceeding OEM quality standards. Built with advanced coatings and hardened construction, these pistons deliver measurable gains in power output and engine longevity.

The MOS2 coating on the skirts is the standout feature here. Unlike standard pistons, this molybdenum disulfide finish actively reduces heat and friction by drawing thermal energy through the piston walls and out the bottom—keeping temperatures down and horsepower up. Combined with specially hardened ring grooves and an improved E-clip design, you're getting durability that matches or exceeds factory specifications.

This is a complete kit per cylinder, so order one for each bore you're rebuilding. Installation is straightforward for anyone with honing and ring-gap experience, though professional machine work is recommended for best results.

• +1mm oversized bore
• Includes piston, rings, pin, clips
• MOS2-coated skirts
• Hardened ring grooves
• Improved E-clip design
• OEM-equivalent quality
• Order one per cylinder
• Additional rings available separately
• Reduces heat and friction
• Increases compression and power