Wiseco 380M07050 Forged Piston Kit Oversize - 2-Stroke 70.50mm 0.50mm 250cc

The Wiseco 380M07050 is a 2-Stroke Forged Series Piston Kit designed for 250cc engines, featuring a 70.50mm actual bore — a +0.50mm oversize over the standard 70.00mm bore. Engineered, forged, and machined in the USA at Wiseco's facility in Mentor, OH, this piston kit is purpose-built for each specific 2-stroke powersports engine to deliver the performance and durability Wiseco is known for.

Wiseco is the only aftermarket piston manufacturer in the United States that produces pistons strictly using the forging process. Starting with aerospace-grade, high-silicon aluminum alloy, the forging process compresses the material's molecules to increase density and align grain flow — resulting in superior resistance to impact and fatigue, and improved ultimate strength and ductility.

Key Features:

• Bore: 70.50mm actual (+0.50mm oversize); standard bore 70.00mm
• Displacement: 250cc
• Stroke: 64.00mm
• Forged from high-silicon, aerospace-grade aluminum alloy for maximum strength and reduced weight
• Dedicated forgings with lightening operations for an optimized strength-to-weight ratio
• CNC machined for high precision and tight tolerances
• Optimized piston shape and skirt profile for maximum horsepower and torque
• Engineered, forged, and machined in the USA (Mentor, OH)

Kit Includes:

• Forged piston
• Ring Set — Part No. 2776CD (70.50mm)
• Wrist Pin — Part No. S343 (18mm x 2.362 in.)
• Round Wire Pin Locks — Part No. CW18 (18mm, pair)

Note: Oversize pistons require cylinder boring or sleeving. Wiseco rings, clips, and wrist pins are designed to fit Wiseco pistons only; ring types are not interchangeable between Wiseco ring series.