Wiseco Pistons PK1159 Piston Kit for Yamaha PW50 40.5mm 2-Stroke

The Wiseco PK1159 is a complete 40.5mm 2-stroke piston kit designed specifically for Yamaha PW50 models through 2009. This comprehensive kit includes a forged piston and top-end gasket kit, providing everything needed for a complete top-end rebuild.

Key Features:

• 40.5mm bore diameter for precise fitment
• Forged in-house for superior strength and durability
• Condensed grain structure aligned to part features for maximum impact and fatigue resistance
• Optimized strength-to-weight ratio for enhanced performance
• Includes complete top-end gasket kit for convenient installation
• Proprietary skirt coating for reduced friction and extended wear

Why Forged Pistons Matter:

Wiseco's forged pistons deliver substantially greater toughness and durability compared to cast alternatives. The forging process creates a condensed grain structure that resists catastrophic failure under high-stress conditions. Where cast pistons are brittle and prone to sudden failure when material limits are exceeded, forged pistons provide superior mechanical properties and reliability in demanding applications.

Manufacturing Excellence:

Every Wiseco piston is forged and finished in the USA with complete in-house control over the entire manufacturing process. From raw material to skirt-coated finished component, Wiseco maintains rigorous quality standards. In-house dyno testing enables continuous development of advanced shapes, coatings, and components that lead the powersports industry.

Designed for youth dirt bike applications, the PK1159 provides the durability and performance needed to keep Yamaha PW50 models running reliably season after season.