Wiseco Pistons PK1845 Compression Piston Kit for Yamaha - 14 1 77mm YZ250F

The Wiseco PK1845 is a high-performance forged piston kit designed for 2008-2010 Yamaha YZ250F motorcycles. This complete top-end kit features a 77.00mm bore diameter with an aggressive 14.0:1 compression ratio, engineered to maximize power output and throttle response for serious motocross racing.

Complete Top-End Kit Includes:

• Forged piston (Part #4976M) with precision-machined skirt coating
• Piston rings, wrist pin, and circlips
• Complete top-end gasket set for professional installation

Wiseco Forged Piston Advantages:

• 100% made in the USA with in-house forging and tooling production
• Superior strength and durability compared to cast pistons
• Condensed grain structure aligned to part features for maximum impact resistance
• Optimized strength-to-weight ratio for reduced reciprocating mass
• Advanced skirt coatings reduce friction and cylinder wall wear
• Dyno-tested design ensures proven performance under extreme racing conditions

Wiseco pistons are forged from aerospace-grade aluminum alloy using state-of-the-art manufacturing processes that create a grain structure far superior to brittle cast pistons. This forged construction provides the toughness and fatigue resistance required for high-performance four-stroke racing applications where failure is not an option.