Yamaha Phazer TRX MTX GT Piston Kit - Wiseco - 12.5:1 CR, 77.00 mm Bore (`08-`12) is a complete forged piston kit engineered for Yamaha 2008–2012 Phazer, TRX, MTX and GT models. This kit provides a direct-fit forged piston with the specified compression ratio and bore size for rebuilds or performance-focused builds.

Part of Wiseco's Forged Series, this 4-stroke piston kit is built for strength and reliability across a range of small-engine applications. The forging process increases material density and resistance to stress, contributing to long service life under higher loads. The kit arrives complete with wrist pin, rings and circlips so you have the hardware needed for installation. The 12.5:1 compression ratio and 77.00 mm bore match the specified Yamaha models, making it suitable for users looking to maintain or restore engine performance with OEM-fit components.

Features

• Forged piston construction for improved strength and durability
• Complete kit: piston, wrist pin, rings and circlips included
• 12.5:1 compression ratio; 77.00 mm bore — fits 2008–2012 Yamaha Phazer, TRX, MTX, GT
• Designed for 4-stroke applications across ATVs, snowmobiles and similar engines

If you have questions or need help confirming fitment, call us directly—our parts specialists can assist you. 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 are thinking about 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