Yamaha YFM350 Warrior Piston Kit - Wiseco - 10.25:1 Compression Ratio, 83.00 mm Bore - 87-13. This forged Wiseco piston kit is made to fit YFM350 Warrior and Raptor models (’87-13) and serves as a direct-fit replacement for standard 83.00 mm bore engines.

Wiseco's forged 4-stroke pistons are engineered for specific powersports applications and manufactured to tight tolerances in Mentor, OH. This kit is designed to restore or maintain engine compression and strength through improved tensile properties of the forging. Included components make a rebuild straightforward: piston, rings, wrist pin(s), and circlips. The precision machining and material selection are intended to provide consistent ring seal and long service life under normal riding conditions, making it a practical choice for repair, refresh, or mild performance-oriented builds.

Features

• Wiseco forged 4-stroke piston designed for Yamaha YFM350 Warrior/Raptor (’87-13)
• 83.00 mm bore, 10.25:1 compression ratio (standard bore application)
• Includes piston rings, wrist pin(s), and circlips for complete assembly
• Engineered and machined in the USA (Mentor, OH) to application-specific tolerances
• Improved tensile strength of forged material for durability in everyday riding

If you have questions about fitment, installation, or compatibility with your build, please call us — we’re happy to help. We have two service locations offering installation and customization services: Austin, Texas and the Los Angeles, California area. Call us at 512-982-9393 (TX) or 562-981-6800 (CA) to discuss your project or to schedule service.

If you are thinking about purchasing multiple items, contact us for shipping discounts. We install on premises at both locations.

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