Wiseco WK1007 Pro-Lite Forged Piston Kit for Kawasaki JS440 & JS440SX 71.5mm Bore

The Wiseco WK1007 is a Pro-Lite forged 2-stroke piston kit designed for the Kawasaki JS440 and JS440SX personal watercraft engines. This kit features a 71.5mm bore (423M series), making it an oversize replacement ideal for engines with worn or bored cylinders. Engineered, forged, and machined in the USA at Wiseco's Mentor, OH facility, this piston kit delivers the strength, precision, and reliability that Wiseco has been known for since 1941.

Key Features:

• Pro-Lite forged construction — forged from high-silicon, low-expansion aerospace aluminum alloy for superior tensile strength and reduced weight compared to cast alternatives
• 71.5mm bore (3.5mm oversize) — engineered for bored-out or resleeved Kawasaki JS440 and JS440SX cylinders
• CNC-machined cam profile — precision-turned for optimal piston shape, peak horsepower, and extended service life
• Dedicated forging — application-specific forging optimizes the strength-to-weight ratio for this exact engine
• Compatible with multiple cylinder types — suitable for cast iron, chrome, Nikasil, and boron composite cylinder bore compositions
• Complete kit — includes high-quality piston ring(s), wrist pin(s), and circlips for a straightforward top-end rebuild
• Made in the USA — precision crafted at Wiseco's state-of-the-art manufacturing facility in Mentor, Ohio

The Wiseco WK1007 Pro-Lite piston kit is the go-to solution for restoring or upgrading the top end of your Kawasaki JS440 or JS440SX PWC engine. Whether you're rebuilding a worn engine or taking advantage of an oversize bore, this kit provides everything needed for a complete, reliable top-end rebuild.