Wiseco K1179 Piston Kit for Yamaha XS1100 +2.5mm Oversize Forged

The Wiseco K1179 is a complete forged piston kit designed for the Yamaha XS1100, offered in a +2.5mm oversize bore specification. Wiseco's forged pistons are a trusted upgrade for riders looking to restore or improve engine performance with components built to exceed OEM standards.

Key Features:

• High-Silicon Forged Aluminum Construction: Forged from high-silicon, low-expansion aluminum alloy for superior strength, reduced weight, improved heat transfer, and extended service life compared to cast pistons.
• Diamond-Turned CNC Finish: Each piston is diamond-turned on CNC computer-controlled lathes, ensuring a precise finish with no size variation from piston to piston.
• Universal Cylinder Compatibility: Engineered to work confidently in all modern cylinder bore compositions, including cast iron, chrome, Nikasil, and boron composite cylinders.
• Oversize Bore Option: The +2.5mm oversize spec extends the service life of worn cast iron-lined cylinders; chrome, Nikasil, and boron composite cylinders can be re-sleeved to accept this oversize piston.
• Complete Kit: Includes piston(s), rings, circlips, and wrist pin (wrist pin included unless otherwise noted).

Wiseco manufactures all pistons at their state-of-the-art computerized facility, producing forged components trusted by both high-performance racers and recreational riders. The K1179 kit is a straightforward solution for a top-end rebuild on the Yamaha XS1100 when boring out to the +2.5mm oversize is required.