Wiseco SK1238 Forged Piston Kit for Ski-Doo - 79.00mm 2-Stroke 670

The Wiseco SK1238 is a complete 2-stroke forged piston kit designed for Ski-Doo snowmobiles equipped with the 670cc engine. Featuring a 79.00mm actual bore diameter (1.00mm oversize), this kit provides everything needed for a top-end rebuild or overbore on a twin-cylinder 670 engine with a 70.00mm stroke.

Kit Includes:

• Forged piston(s)
• High-quality piston ring(s)
• Wrist pin(s)
• Circlips

Key Features:

• USA-engineered and forged — designed, forged, and machined at Wiseco's facility in Mentor, OH
• Forged aluminum construction — delivers superior tensile strength, impact resistance, and fatigue durability compared to cast pistons
• Optimized strength-to-weight ratio — dedicated forgings with lightening operations for maximum performance without added mass
• Condensed grain structure — aligned to the part geometry for higher mechanical properties and resistance to fatigue
• Skirt coating — reduces friction and improves wear resistance under high-performance conditions
• Complete kit — includes all necessary components for overboring or rebuilding your top end

Specifications:

• Bore (Standard): 78.00mm
• Bore (Actual): 79.00mm
• Oversize: 1.00mm
• Stroke: 70.00mm
• Displacement: 686cc
• Cylinders: 2
• Engine Type: 670
• Cross-Reference: 2379M07900, 3110LK

Note: Cylinder sleeves must be purchased separately. Wiseco's forged 2-stroke pistons are the product of over 80 years of manufacturing experience, purpose-built for demanding snocross, cross-country racing, and high-performance snowmobile applications.