Wiseco Piston 89mm +2mm Oversize for Yamaha YZ490 1984-1990 546M08900

If you're running a Yamaha YZ490 or WR500 at the edge of its limits, factory pistons won't cut it. This Wiseco forged piston is built to withstand the punishment of competitive racing and aggressive trail riding while delivering measurable gains in horsepower and torque. At 89mm +2mm oversize, it's engineered for serious engine builders and riders who demand reliability under extreme conditions.

The high-silicon aluminum construction combined with E-coat protection on critical surfaces means longer intervals between rebuilds and consistent performance lap after lap. The included titanium nitride-coated rings provide superior wear resistance, while the optimized skirt design ensures predictable power delivery across the entire powerband. This is a complete piston kit—everything you need except the cylinder sleeves—designed by engineers who understand two-stroke demands.

• 89mm +2mm oversize
• Wiseco forged piston
• High-silicon aluminum alloy
• E-coated crown, grooves, bore
• Titanium nitride-coated rings
• Includes wrist pins, circlips
• Yamaha YZ490 1984-1990
• Yamaha WR500 compatible
• Bolt-on installation
• MPN: 546M08900