Yamaha Raptor Piston Kit - Wiseco - 121 CR - `87-`13. A direct-fit forged piston kit designed for Yamaha YFM350 Warrior and Raptor models from 1987–2013, offering reliable strength and consistent performance for 4-stroke applications.

This Wiseco piston kit is engineered specifically for the Yamaha 350 platform and manufactured to tight tolerances. Wiseco’s forged 4-stroke pistons are built from dedicated forgings to optimize strength-to-weight ratio and improved tensile strength for longer service life. The kit is machined in the USA (Mentor, OH) and is intended for an 83.00 mm bore with a 12:1 compression ratio. It’s a complete replacement piston kit that includes piston rings, wrist pin(s), and circlips to simplify installation and ensure correct fitment.

Features

• Forged 4-stroke piston forged for strength and durability
• Designed for Yamaha YFM350 Warrior/Raptor 1987–2013
• 83.00 mm bore, 12:1 compression ratio (121 CR)
• Includes piston rings, wrist pin(s), and circlips
• Engineered and machined in Mentor, OH, USA

This kit is aimed at riders and mechanics who want a dependable replacement or performance-oriented piston built to factory-specific tolerances. It is not a generic piston — the design addresses the needs of the Yamaha 350 4-stroke platform and is backed by Wiseco’s long history in powersports pistons. Follow engine builder specifications for proper installation and break-in procedures.

If you have questions or need fitment guidance, call us directly at 512-982-9393 (TX) or 562-981-6800 (CA). We have two locations — Austin, Texas and the Los Angeles, California area — where we offer installation and customization services. 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