Namura .040 Over Bore Top End Kit for Polaris 570 Sportsman RZR Ranger 100mm

Namura .040 Over Bore Top End Kit for Polaris 570

This top end repair kit overbores the Polaris 570 engine to 100mm, providing a complete cylinder and piston assembly for Sportsman, RZR, and Ranger models.

Overview

The Namura .040 Over Bore Top End Kit is a direct-fit cylinder and piston assembly designed for Polaris 570 engines found in Sportsman, RZR, and Ranger vehicles. It overbores the original 95mm cylinder to 100mm, restoring lost compression and power while eliminating cylinder scoring. This kit is ideal for high-mileage or damaged engines requiring a complete top-end rebuild.

Built For Performance

• Precision-cast cylinder with 100mm bore for increased displacement
• Includes forged piston, rings, wrist pin, and circlips
• Compatible with stock Polaris 570 crankshaft and connecting rod
• Oversized .040 over bore removes cylinder damage and restores compression
• All necessary gaskets included for a complete installation

Fits These Machines

• for Polaris Sportsman 570
• for Polaris RZR 570
• for Polaris Ranger 570

On-The-Job Use

• Restoring power in high-mileage utility and trail vehicles
• Rebuilding engines after top-end failure or overheating
• Upgrading displacement for improved torque in work applications
• Replacing worn cylinders that show scoring or excessive wear

Specs At A Glance

Good To Know

Q: Does this kit require any special tools to install? A: Standard engine rebuild tools are needed, including a torque wrench and piston ring compressor. Always follow the factory service manual for proper assembly.

Q: Can I reuse my old cylinder head with this kit? A: Yes, the existing cylinder head can be reused provided it is in good condition and the gasket surface is clean.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.