Wiseco PK1162 2-Stroke Top End Kit 41.5mm Bore for Yamaha PW50

The Wiseco PK1162 is a complete 2-stroke top end kit designed for the Yamaha PW50, featuring a 41.5mm (1.634") bore forged piston built to outperform OEM components. Wiseco's Pro-Lite forged pistons are engineered, forged, and CNC machined in Mentor, OH, USA, and have been the choice of top race teams across Supercross, Motocross, GNCC, and more.

This PK-series kit includes everything needed to complete a top end rebuild in a single purchase—no need to source individual components separately. The aerospace-grade alloy forging delivers an exceptional strength-to-weight ratio, while the dedicated forging process ensures each piston is purpose-built for the specific dimensions of the PW50 engine.

Kit Includes:

• Forged Pro-Lite piston — 41.5mm bore, CNC machined for optimal cam shape and profile for peak horsepower and service life
• High-performance ring set — precision fit for extended service life and sustained power output
• Alloy wrist pin — precision machined for consistent fit and long-term durability
• Circlips — retaining clips included for complete assembly
• Premium top end needle bearing — precision machined from highest-quality materials for reduced friction and strength
• Complete top end gasket kit — premium materials exceeding OEM sealing standards

Wiseco's aerospace alloy forgings provide improved tensile strength over cast alternatives, resulting in greater reliability under the heat and stress of 2-stroke operation. The PK1162 is a direct fit for the Yamaha PW50 through model year 2009 and is a trusted solution for top end rebuilds requiring performance and longevity beyond stock specifications.