Yamaha YZ450F Piston Kit - Wiseco - 12.51 CR, 95.00 mm Bore (’03–’09) is a forged replacement piston kit designed for Yamaha YZ450F four-stroke engines from 2003 through 2009. It provides OEM-fit dimensions with performance-grade materials suited for rebuilds and track use.

This Wiseco kit is engineered specifically for 4-stroke powersports applications and built to tight tolerances. The forged piston material improves tensile strength for durability under high loads, while the dedicated design optimizes strength-to-weight for the YZ450F platform. The kit includes the piston, high-quality piston rings, wrist pin(s), and circlips, and is forged and machined in Mentor, OH, USA. It fits engines bored to 95.00 mm and is specified at a 12.51:1 compression ratio for the listed model years.

Features

• Forged 4-stroke piston engineered for the Yamaha YZ450F (2003–2009)
• 95.00 mm bore, 12.51:1 compression ratio
• Includes piston rings, wrist pin(s), and circlips
• Forged, machined, and assembled in the USA (Mentor, OH)
• Manufactured to tight tolerances for consistent fit and service life

If you have questions or want help confirming fitment, call us directly at 512-982-9393 (TX) or 562-981-6800 (CA). We have locations in Austin, Texas and the Los Angeles, California area where we offer installation and customization services. If you are considering purchasing multiple items, please contact us for shipping discounts. We install on premises at both locations.

CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov