2 SPI .040 Over Bore Piston Kits for Polaris 500 Snow 1985-2006 488cc 73mm

.040 Over Bore Piston Kits for Polaris

This pair of SPI .040 over bore piston kits is designed for Polaris 500 Snow engines from 1985-2006, offering a 73mm bore size and 488cc displacement for reliable engine rebuilds.

Overview

These SPI .040 over bore piston kits provide a direct replacement for worn pistons in Polaris 500 Snow snowmobiles built between 1985 and 2006. Each kit includes one piston and rings, sized at 73mm (0.040 over) to restore compression and performance after cylinder boring. Perfect for the 488cc engine family, these kits help bring older Polaris snowmobile engines back to life.

Built For Performance

• Cast from high-silicon aluminum alloy for thermal stability
• Precision-machined ring grooves reduce blow-by
• Oversized 73mm (.040 over) compensates for cylinder wear
• Includes piston rings for complete top-end rebuild
• Weight-matched for balanced engine operation

Fits These Machines

• for Polaris 500 Snow (488cc, 73mm bore) – 1985 to 2006 models

On-The-Job Use

• Engine overhaul and top-end rebuilds
• Restoring compression in high-mileage snowmobiles
• Trail riding and recreational snowmobile use

Specs At A Glance

Good To Know

Q: Do these pistons include wrist pins? A: Each piston kit typically includes the piston, rings, and wrist pin; please confirm with your engine's specifications before ordering.

Q: Are these for a standard bore or overbore? A: These are .040 over size (73mm) and require the cylinder to be bored accordingly; they are not for standard bore engines.

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