Wiseco SK1257 Forged Piston Kit for Yamaha Snowmobile - 74.80mm 2-Stroke

The Wiseco SK1257 is a standard bore, 74.80mm 2-stroke forged piston kit designed for Yamaha snowmobile engines. Engineered, forged, and machined entirely in the USA at Wiseco's facility in Mentor, OH, this kit delivers the strength, precision, and reliability demanded by high-performance snowmobile applications including snocross and cross-country racing.

Key Features:

• Standard bore size: 74.80mm for direct OEM replacement at stock displacement
• Forged aluminum construction: Aerospace-grade aluminum is compressed during forging, aligning grain flow and increasing material density for superior strength, impact resistance, and fatigue life compared to cast alternatives
• Optimized strength-to-weight ratio: Dedicated forgings with additional lightening operations keep reciprocating mass low without sacrificing durability
• USA-made forging and tooling: Wiseco controls every step of production — from raw aluminum bar through skirt coating — ensuring consistent quality and tight tolerances
• In-house dyno development: Each design is validated through rigorous R&D and finite element modeling software to maximize performance for the specific application
• Complete kit: Includes high-quality piston ring(s), wrist pin(s), and circlips matched specifically to Wiseco forged pistons for a true one-stop top-end solution
• Cross-reference piston number: 2388M07480

Wiseco has been the trusted name in forged piston technology since 1941 and remains the only aftermarket piston manufacturer in the United States to use exclusively the forging process. The SK1257 kit is purpose-built for Yamaha 2-stroke snowmobile engines and is the preferred choice of professional race teams competing at the highest levels of the sport.