Wiseco WK1139 Forged Piston Kit 82.00mm Bore Polaris 700cc Twin PWC

The Wiseco WK1139 is a complete forged piston kit designed for Polaris 700cc twin-cylinder personal watercraft engines, featuring an 82.00mm bore. This oversize kit is engineered for engines requiring a bore rebuild, restoring or improving upon original displacement and performance.

Wiseco pistons are forged from a high-silicon, low-expansion aluminum alloy, delivering superior tensile strength, reduced reciprocating weight, improved heat transfer, and extended service life compared to cast alternatives. Each piston is finish-machined on CNC turning centers to exacting tolerances, ensuring consistent sizing and a precision fit across all cylinder bore types—including cast iron, chrome, Nikasil, and boron composite.

Key Features:

• Forged high-silicon aluminum construction for superior strength and durability
• 82.00mm oversize bore for use in rebuilt or re-sleeved 700cc Polaris PWC cylinders
• CNC diamond-turned finish for precise sizing with zero variation
• Compatible with cast iron, chrome, Nikasil, and boron composite cylinder bores
• Engineered, forged, and machined in the USA at Wiseco's Mentor, OH facility
• Complete kit includes piston, rings, wrist pin, and retaining clips

Wiseco's oversize piston range allows cast iron-lined cylinders to be bored and honed to accept the new piston, while chrome, Nikasil, and boron composite cylinders can be re-sleeved to accommodate oversize fitments. Whether performing a routine top-end rebuild or extracting more performance, the WK1139 delivers the precision and reliability that Wiseco is known for across powersports and marine applications.