Yamaha WR250F Piston Kit - Wiseco - 7700YC, 13.5:1 CR, 77.00 mm Bore (05-11) is a forged replacement piston kit engineered to meet the demands of 4-stroke off-road engines. This Wiseco kit is designed specifically for WR250F models from 2005 through 2011 and includes the components needed for a direct fit install.

Built from dedicated forged alloys in Mentor, Ohio, the Wiseco 7700YC piston offers improved tensile strength and tight machining tolerances for consistent performance and durability under racing and trail conditions. The kit is tailored to the WR250F’s bore size and compression ratio (77.00 mm bore, 13.5:1 CR), and ships complete with high-quality rings, wrist pin, and circlips for straightforward assembly. Designed for application-specific fitment, this piston balances strength-to-weight considerations and is intended for riders who want a reliable, OEM-style replacement or a foundation for engine work.

Features

• Forged Wiseco piston specific to Yamaha WR250F 2005–2011
• 77.00 mm bore, 13.5:1 compression ratio (7700YC)
• Includes piston rings, wrist pin, and circlips
• Engineered and machined in the USA (Mentor, OH)
• Improved tensile strength and tight tolerances for durability

If you have questions or want help confirming fitment, call us directly — Texas: 512-982-9393, California: 562-981-6800. We have two locations offering installation and customization services in Austin, Texas and the Los Angeles, California area. 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