Namura Standard Bore Piston Kit for Polaris Trail Boss 250 fits 1985-1999 72mm

Namura Standard Bore Piston Kit for Polaris

This standard bore piston kit replaces the original piston in Polaris Trail Boss 250 ATVs from 1985 to 1999, using a 72mm bore diameter to maintain factory specifications.

Overview

The standard bore piston kit for Polaris Trail Boss 250 is a direct replacement for engines that do not require oversize pistons. This 72mm piston kit restores compression and performance in 1985-1999 models.

Built For Performance

• Manufactured from high-silicon aluminum alloy for durability and heat resistance
• Precision ground piston skirt ensures proper cylinder wall contact
• Includes piston pin and retaining clips for complete installation
• Standard 72mm bore size matches original factory dimensions
• Designed for Polaris Trail Boss 250 engines
• Rings included for immediate use

Fits These Machines

• for Polaris Trail Boss 250 (1985-1999)

On-The-Job Use

• Restores lost compression in high-mileage Trail Boss engines
• Ideal for engine rebuilds after cylinder scoring or ring failure
• Commonly used during full top-end overhauls on Polaris ATVs
• Provides reliable power for trail riding and utility use

Specs At A Glance

Good To Know

Q: Do I need to re-use my old piston pin? A: It is recommended to use the included pin and clips for proper fit. Always follow your engine manual for assembly torque specs.

Q: Is any special preparation required for the cylinder? A: The cylinder should be honed to the correct finish for a 72mm standard piston. Check ring end gap during assembly.

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