Namura Standard Bore Piston Kit for Polaris 400L / Big Boss 400L 1994-1997 83mm

Standard Bore Piston Kit for Polaris

This is a replacement standard bore piston kit for Polaris 400L and Big Boss 400L ATVs from 1994-1997, featuring an 83mm bore size to restore engine compression and performance.

Overview

This standard bore piston kit is a direct replacement for Polaris 400L and Big Boss 400L models built between 1994 and 1997. It includes a piston, rings, wrist pin, and circlips to rebuild the top end and bring back lost power. Designed for the 83mm bore, this piston kit ensures reliable operation in utility and recreational ATV applications.

Built For Performance

• 83mm bore size matches original Polaris 400L specifications
• Durable cast piston withstands high combustion temperatures
• Precision-machined wrist pin ensures smooth connecting rod articulation
• High-quality ring set reduces blow-by and improves compression
• Kit includes all necessary components for a complete top-end rebuild

Fits These Machines

• for Polaris 400L 1994-1997
• for Polaris Big Boss 400L 1994-1997

On-The-Job Use

• Trail riding and recreational ATV use
• Farm and ranch utility tasks requiring reliable engine output
• Rebuilding worn top ends to restore lost horsepower
• Competition or heavy-use machines needing periodic piston replacement

Specs At A Glance

Good To Know

Q: Is this piston kit a direct fit for my Polaris 400L? A: Yes, it is designed as a direct replacement for 1994-1997 Polaris 400L and Big Boss 400L models with the 83mm bore, but verify your engine serial number to confirm compatibility.

Q: Do I need any special tools to install this piston kit? A: Standard engine rebuilding tools such as a piston ring compressor and torque wrench are recommended for proper installation.

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