Wiseco 4920M07700 KX250F Flat Top Forged Piston Kit 77mm 13.5:1 CR

The Wiseco 4920M07700 is a high-performance forged piston kit engineered for the Kawasaki KX250F 4-valve motocross engine. Featuring a flat top design with a 13.5:1 compression ratio and a 77.00mm standard bore, this piston is purpose-built for riders who demand maximum power and reliability from their 250cc four-stroke engine.

Key Features:

• Forged aerospace-grade aluminum — high-silicon, low-expansion alloy offers superior strength, reduced weight, and improved heat transfer over cast alternatives
• 77.00mm standard bore with a 13.5:1 compression ratio for optimized combustion efficiency and strong throttle response
• Flat top piston crown designed for the KX250F 4-valve combustion chamber geometry
• CNC diamond-turned finish ensures tight tolerances and consistent sizing with no variation
• Compatible with all cylinder bore compositions — cast iron, chrome, Nikasil, and boron composite cylinders
• Complete kit includes piston, rings, wrist pin, and circlips — everything needed for a full top-end rebuild
• Manufactured entirely in the USA — Wiseco forges all pistons and forge tooling in-house for full quality control from raw material to finished part

Wiseco utilizes 3D design techniques and finite element modeling software to maximize strength while minimizing weight in every piston design. The result is a forged piston that outperforms OEM and cast alternatives in high-RPM, high-stress racing and trail applications alike.