Yamaha YZ250F Piston Kit - Wiseco - 7700YC, 13.5:1 CR, 77.00 mm Bore ('05–'11) is a direct-fit forged piston kit engineered for Yamaha YZ250F four-stroke applications. This Wiseco kit replaces the stock piston with a high-strength, precision-machined component for reliable performance in 2005–2011 YZ250F models.

Wiseco forged 4-stroke pistons are manufactured to tight tolerances and built for specific engine applications. The 7700YC piston features improved tensile strength and a strength-to-weight-optimized forging that supports durability under race and trail conditions without overstating capabilities. The kit includes high-quality piston rings, a wrist pin, and circlips, and is engineered, forged, and machined in Mentor, Ohio, USA. This makes it a solid choice for enthusiasts looking to maintain or restore proper compression and component fitment in their 77.00 mm bore YZ250F.

Features

• Fitment: Yamaha YZ250F 2005–2011 (77.00 mm bore)
• Compression Ratio: 13.5:1
• Wiseco forged construction — engineered for specific 4-stroke engines
• Includes piston rings, wrist pin, and circlips
• Forged, machined, and finished in the USA (Mentor, OH)

If you have questions about fitment or installation, call us — we’re happy to help. We offer installation and customization services at both of our locations in Austin, Texas and the Los Angeles, California area. Call: 512-982-9393 (TX) or 562-981-6800 (CA). If you’re considering multiple items, contact us about shipping discounts. We install on premises at both locations.

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