Wiseco PK1379 Top End Piston Kit Kawasaki - 66.4mm 2005-2007 KX250

The Wiseco PK1379 is a complete top end kit engineered for the 2005–2007 Kawasaki KX250 two-stroke motocross bike. Featuring a 66.4mm bore (843M), this kit is built from aerospace-grade aluminum alloy, delivering an optimal strength-to-weight ratio critical for high-revving two-stroke competition engines.

Wiseco's dedicated forging process produces a piston with tight tolerances and consistent dimensions, ensuring reliable sealing and sustained power output. The kit is CNC machined to exacting specifications, with an optimized cam shape and skirt profile designed to maximize peak horsepower while extending component service life.

Kit Includes:

• Forged piston — Aerospace aluminum alloy construction for superior strength and reduced weight
• High-performance ring set — Engineered for extended service life and consistent power delivery
• Top end needle bearing — Precision machined for reduced friction and long-term durability
• Alloy wrist pin — Consistently true, hardened, and dimensionally stable under racing loads
• Wiseco top end gasket kit — Premium materials exceeding OEM sealing standards

The PK1379 is a race-proven solution trusted by professional and amateur motocross teams across all forms of competition. Whether you're rebuilding after a season of hard riding or preparing for race day, this kit provides everything needed for a complete top end refresh on the KX250.