Wiseco 85.50mm 10:1 Piston Kit for Honda TRX400EX 1999-2008 PK1032

When you're rebuilding a TRX400EX top-end for racing or high-performance riding, factory pistons won't cut it. Wiseco's forged piston kit delivers the thermal stability and durability needed to handle elevated RPMs and sustained power demands without sacrificing reliability. This complete kit includes everything required for a proper engine rebuild, eliminating guesswork and compatibility issues.

The forged high-silicone construction reduces thermal expansion while maintaining the strength required for aggressive riding. All components—piston, rings, wrist pins, circlips, and gasket kit—are engineered to work as a system, which is why Wiseco rings must be used with Wiseco pistons. The ring design is proprietary and non-interchangeable, ensuring precise fit and preventing performance loss or premature wear.

Bolt-on installation requires standard top-end teardown and reassembly. If you're unfamiliar with engine work, professional installation is strongly recommended to ensure proper ring seating and gasket torque specifications.

• Bore diameter: 85.50mm
• Compression ratio: 10:1
• Forged high-silicone construction
• Complete kit included
• Forged piston, rings, pins
• Wrist pin circlips included
• Top-end gasket kit included
• Wiseco rings required
• Non-interchangeable ring design
• Honda TRX400EX 1999-2008
• Racing/high-performance rated
• Reduced thermal expansion