Wiseco PK1805 Pro-Lite Top End Piston Kit Bore - 2-Stroke 56.5mm

The Wiseco PK1805 is a Pro-Lite forged 2-stroke top end piston kit with a 56.5mm (559M) bore, engineered for the Yamaha YZ125. This complete top end kit includes everything needed for a proper overbore or top-end rebuild, delivering the performance and reliability that Wiseco has built its reputation on since 1941.

Wiseco Pro-Lite forged pistons are the result of decades of 2-stroke piston manufacturing experience. Starting from aerospace-grade aluminum, the forging process compresses and aligns the material's molecular grain structure, producing a piston with superior tensile strength, improved impact resistance, and excellent ductility compared to cast alternatives.

Kit Contents:

• Forged Pro-Lite piston — 56.5mm bore diameter
• Piston ring(s)
• Wrist pin
• Circlips
• Top-end gasket set

Key Features:

• Forged from high-silicon, low-expansion aluminum for superior strength and reduced weight
• Lightweight forging design optimizes strength-to-weight ratio for instant throttle response
• Engineered, forged, and machined in the USA (Mentor, OH)
• Diamond-turned CNC finish ensures precise bore sizing with no variation
• Dedicated forging design built specifically for the YZ125 engine
• Complete kit — all components required for a full top-end rebuild included

The Wiseco PK1805 Pro-Lite top end kit is the go-to choice for riders seeking a balance of performance, reliability, and value in a forged 2-stroke piston kit.