Namura .040 Over Bore Piston Kit for Kawasaki KLX400, KLX400R & KLX400SR 91mm

Namura .040 Over Bore Piston Kit for Kawasaki

This aftermarket piston kit with a 91mm bore and .040 over size is designed to restore compression and performance in compatible Kawasaki KLX400 series engines. It provides a reliable replacement for worn pistons in KLX400, KLX400R, and KLX400SR models.

Overview

The Namura .040 over bore piston kit provides a precision-machined 91mm piston for Kawasaki KLX400 motorcycles. It serves as a reliable replacement for worn pistons, restoring compression and performance. This piston kit is designed for off-road and trail riding applications.

Built For Performance

• 91mm bore diameter with .040 oversize for increased displacement
• High-strength aluminum alloy construction for durability
• Precision-ground rings for optimal sealing
• Designed to match OEM specifications for easy installation
• Includes piston, rings, wrist pin, and clips

Fits These Machines

• for Kawasaki KLX400
• for Kawasaki KLX400R
• for Kawasaki KLX400SR

On-The-Job Use

• Trail riding and off-road racing
• Engine rebuilds and top-end overhauls
• Restoring lost compression in high-mileage engines
• Enhancing engine performance for competitive use

Specs At A Glance

Good To Know

Q: Does this kit include a wrist pin? A: Yes, the kit includes a wrist pin, circlips, and piston rings for a complete replacement.

Q: Can this piston be used with stock cylinder? A: The .040 over bore requires your cylinder to be bored to the corresponding size; it is not a direct drop-in replacement for a standard cylinder.

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