Wiseco Pistons PK1557 Pro-Lite Forged Piston Kit Oversize - 49mm 2.00mm 2-Stroke

The Wiseco PK1557 is a Pro-Lite forged piston kit designed for 1993–2001 Yamaha YZ80 2-stroke engines requiring an overbored cylinder rebuild. With a 49.00mm bore diameter at +2.00mm (.080") oversize, this kit delivers the precision fitment and durability that Wiseco is trusted for by racers and professional engine builders alike.

Wiseco's Pro-Lite line is forged from high-silicone aluminum bar stock right here in the USA, resulting in a piston that runs cooler, expands less at operating temperature, and withstands the punishment of hard 2-stroke riding far better than cast alternatives. Dedicated forgings and targeted lightening operations optimize the strength-to-weight ratio for a responsive, high-revving powerplant.

Kit Includes:

• Forged Pro-Lite piston — 49.00mm bore, +2.00mm oversize
• Piston ring(s) — Wiseco rings matched specifically to this piston (not interchangeable with other ring types)
• Wrist pin — precision-ground for exact fit
• Circlips — retaining clips for secure wrist pin installation

Key Specifications:

• Bore Size: 49.00mm
• Oversize: +2.00mm / +0.080"
• Forging Code: 646M
• Piston Series: Pro-Lite
• Piston Material: Forged aluminum (high-silicone)
• Engine Type: 2-Stroke

Engineered, forged, and machined in the USA at Wiseco's facility in Mentor, OH, the PK1557 is the right choice for a performance-focused top-end rebuild. Note: Wiseco rings are not interchangeable between ring types — always use the rings included with or specified for this piston kit.