Wiseco Pistons 4904M07700 High-Performance Piston Kit Compression - 77mm 13.5 1 250cc

The Wiseco 4904M07700 is a high-performance forged piston kit designed for 250cc four-stroke dirt bike engines with a standard bore size of 77.00mm and a 13.5:1 compression ratio. This complete piston kit is engineered for maximum durability and power output in demanding off-road riding and racing conditions.

Premium Forged Construction:

Wiseco pistons are forged from high-silicon, low-expansion aerospace-grade aluminum alloy, offering superior strength compared to cast pistons while reducing weight for higher RPM capability. The forging process compresses the material molecules, increasing density and aligning grain flow for enhanced impact resistance, fatigue resistance, and improved ductility under extreme stress.

Advanced Performance Features:

• Dome design for optimized flame travel and combustion efficiency
• Chrome-plated wrist pin with horizontal slot pin oiling system
• Armor Glide skirt coating for reduced friction and scuff resistance
• Pressure seal groove design for maximum ring seal
• CNC diamond-turned finish ensures perfect sizing with no variation
• Race-ready dome finish with smooth edges for improved combustion flow
• Compatible with all modern cylinder bore compositions including cast iron, chrome, Nikasil, and boron composite

Complete Kit Includes:

Each Wiseco four-stroke piston kit comes complete with one forged piston, dedicated ring set, chrome-plated wrist pin, and two circlips. This kit contains all essential components needed for your top-end rebuild. Note that only Wiseco replacement rings can be used with Wiseco pistons, and top-end gaskets are sold separately.

Technical Specifications:

• Bore Size: 77.00mm (Standard)
• Compression Ratio: 13.5:1
• Displacement: 250cc
• Stroke: 53.60mm
• Cylinders: 1