Wiseco 40099M09800 4-Stroke Forged Piston Kit 98.00mm Standard Bore Stock Compression

The Wiseco 40099M09800 is a 4-Stroke Forged Series Piston Kit featuring a 98.00mm standard bore at stock compression ratio. Engineered, forged, and machined in the USA at Wiseco's facility in Mentor, OH, this piston kit is designed for each specific powersports engine application and built to the tightest manufacturing tolerances for an optimal combination of performance and long-term durability.

Key Features:

• Aerospace-grade forged construction — made from high-silicon, low-expansion aluminum alloy for superior strength, reduced weight, improved heat transfer, and extended service life
• Dedicated forging design — optimized strength-to-weight ratio with an innovative piston skirt profile engineered to maximize horsepower and torque output
• Diamond-turned CNC finish — precision machined on computer-controlled turning centers for a perfect bore fit with zero size variation
• Universal cylinder compatibility — can be installed in cast iron, chrome, Nikasil, and boron composite cylinder bore compositions with confidence
• Complete kit — includes piston, high-quality piston rings, wrist pin, and circlips; everything needed to complete the piston repair in one package
• Made in the USA — engineered and manufactured at Wiseco's state-of-the-art facility in Mentor, Ohio

Wiseco forged pistons offer a significant advantage over cast alternatives. Forgings feature a condensed grain structure aligned to the part geometry, producing higher mechanical properties and superior resistance to impact and fatigue — critical qualities for high-demand ATV and powersports applications. Note: oversize pistons require cylinder re-sleeving.