Wiseco PK1873 Top End Piston Kit - 97mm 13.5 1 YZ450F 40002M

The Wiseco PK1873 is a complete top end piston kit designed for the Yamaha YZ450F, featuring a 97mm overbore and a high-compression 13.5:1 ratio. This kit provides everything needed to overhaul or rebuild the top end of your 4-stroke dirt bike engine with confidence.

Key Features:

• Forged piston engineered and machined in the USA (Mentor, OH) for superior strength and performance
• 13.5:1 compression ratio at 97mm bore — ideal for performance-oriented rebuilds and overbore applications
• ArmorGlide skirt coating reduces friction and noise while contributing to increased horsepower
• Dedicated forging optimizes strength-to-weight ratio using aerospace-grade alloy construction
• Includes: forged piston, high-performance ring set, wrist pin, circlips, and top end gasket set
• Designed and built for this specific 4-stroke powersports engine application
• Improved tensile strength of forged material optimizes service life under race conditions

Note: A 97mm overbore requires professional cylinder boring and Nikasil re-plating or a new cylinder sleeve. Premium pump fuel is recommended when running compression ratios up to 13.5:1. Always inspect and measure your cylinder before ordering. Piston SKU reference: 40002M.