Wiseco WK1315 Forged Piston Kit Overbore - 1169cc 1.5mm 85.50mm

The Wiseco WK1315 is a complete forged piston kit designed for Yamaha 1200 personal watercraft engines, delivering a 1169cc displacement with a +1.5mm overbore to 85.50mm. Built for performance-minded riders and competitive racers, this kit pairs race-proven piston design with precision CNC manufacturing for a drop-in upgrade over stock.

Key Features:

• Forged High-Silicon Aluminum Construction: Each piston is forged from a high-silicon, low-expansion aluminum alloy, providing superior strength, reduced weight, improved heat transfer, and extended service life compared to cast alternatives.
• +1.5mm Overbore – 85.50mm Bore Diameter: Designed for engines bored 1.5mm over stock, bringing displacement to 1169cc for added power and performance.
• CNC Diamond-Turned Finish: Computer-controlled turning centers produce a precision surface finish with consistent sizing, ensuring proper fit and minimal break-in wear.
• Compatible with Multiple Cylinder Bore Types: Suitable for use in cast iron, chrome, Nikasil, and boron composite cylinder bore compositions without modification.
• Resleeve-Ready Oversize Design: Supports cylinder resleeving of chrome, Nikasil, and boron composite cylinders, extending engine life and accepting Wiseco oversize fitments.
• Complete Kit: Includes 3x Wiseco 3368KD piston ring sets at 85.50mm bore size — everything needed for a full top-end rebuild.

Wiseco has been manufacturing performance forged pistons for powersports applications for over 80 years. The WK1315 reflects that heritage, offering the same forged quality trusted by professional racers in a kit sized specifically for the Yamaha 1200 platform.