Wiseco PK1044 Top-End Piston Kit 75.00mm 10.25:1 CR Honda TRX300 FourTrax

The Wiseco PK1044 is a complete top-end piston kit designed for the Honda TRX300 FourTrax (1988–2000). This kit provides a 1.00mm oversize bore of 75.00mm (over the standard 74.00mm) at a 10.25:1 compression ratio, making it ideal for cylinder overbore and top-end rebuild applications. Cylinder boring and honing is required prior to installation.

Kit Specifications:

• Bore Size: 75.00mm (1.00mm oversize)
• Standard Bore: 74.00mm
• Stroke: 65.5mm
• Displacement: 289cc
• Compression Ratio: 10.25:1
• Wrist Pin: 17mm (Part No. S523)
• Compatible with: 2WD and 4WD models

Kit Contents:

• Forged piston (Part No. 4629M07500)
• Piston ring set — 75.00mm (Part No. 2953XC)
• 17mm wrist pin (Part No. S523)
• Round wire pin locks / circlips — 17mm (Part No. CW17)
• Top-end gasket kit for Honda TRX300 88–00 (Part No. W5573)

Why Wiseco Forged Pistons?

• Engineered, forged, and machined in the USA in Mentor, OH
• Designed for each specific 4-stroke powersports engine application
• Built to the tightest tolerances for performance and longevity
• Improved tensile strength of forged material optimizes strength and service life
• Dedicated forgings deliver an optimized strength-to-weight ratio
• Forged grain structure resists impact and fatigue far better than cast alternatives

Unlike cast pistons, Wiseco's forged pistons feature a condensed, aligned grain structure that improves mechanical properties and resistance to impact and fatigue — critical qualities for demanding ATV applications. This complete kit supplies everything needed for a professional top-end rebuild, eliminating the need to source individual components separately.

Note: Cylinder boring and honing to 75.00mm is required. California residents — see Prop 65 warning.