Wiseco PK1042 74.0mm Forged Top End Piston Kit for Honda TRX300 FourTrax

The Wiseco PK1042 is a complete forged top end piston kit engineered specifically for the Honda TRX300 FourTrax ATV. With a 74.00mm bore diameter and 10.25:1 compression ratio, this kit delivers everything needed for a proper top end rebuild or overbore project in a single, convenient package.

Wiseco is the only aftermarket piston manufacturer in the United States that produces pistons exclusively through the forging process. Starting with aerospace-grade aluminum, forging compresses the material's molecules, increasing density and aligning the grain flow of the alloy — resulting in superior resistance to impact and fatigue compared to cast alternatives. Each forging is purpose-designed to optimize the strength-to-weight ratio for this specific engine application.

Kit Includes:

• High-performance forged piston (74.00mm bore, Wiseco piston number 4629M)
• Piston rings (fits Wiseco pistons only — rings are not interchangeable with other brands)
• Wrist pin(s)
• Circlips
• Top end gasket set

Key Specifications:

• Bore Size: 74.00mm
• Compression Ratio: 10.25:1
• Wiseco Piston Number: 4629M
• Engineered, forged, and machined in the USA (Mentor, OH)

Every Wiseco piston design is validated through in-house dynamometer testing, ensuring each kit meets the demands of real-world powersports use. Whether you're rebuilding a worn top end or overboring for more displacement, the PK1042 provides a direct-fit, performance-grade solution for the Honda TRX300 FourTrax.