Namura .020 Over Bore Piston Kit for Polaris Big Boss 250 4x6 6x6 1989-93 72.5mm

.020 Over Bore Piston Kit (72.5mm) for Polaris Big Boss 250

This Namura .020 oversize piston kit is designed for Polaris Big Boss 250 4x6 and 6x6 models from 1989 to 1993, providing a 72.5mm bore for engines that require an overbore after wear.

Overview

This .020 over bore piston kit from Namura is built for Polaris Big Boss 250 ATVs, offering a precise 72.5mm piston that restores compression and power after cylinder wear. It includes the piston, rings, wrist pin, and circlips for a complete top-end overhaul.

Built For Performance

• Oversized 72.5mm piston machined from durable aluminum alloy
• Moly-coated skirt reduces friction and promotes long life
• Chrome-plated rings provide excellent sealing and wear resistance
• Wrist pin and circlips included for secure installation
• Designed to match OEM .020 over specifications

Fits These Machines

• for Polaris Big Boss 250 4x6 (1989-1993)
• for Polaris Big Boss 250 6x6 (1989-1993)

Specs At A Glance

Good To Know

Q: Is this kit suitable for a standard bore cylinder? A: No, this .020 over piston is intended for cylinders that have been machined to 72.5mm, typically after wear or damage.

Q: Does the kit come with a gasket set? A: No, gaskets are not included; we recommend ordering a top-end gasket set separately for your Polaris Big Boss 250.

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