Namura .040 Over Bore Piston & Gasket Kit for Honda Rancher 420 2009-2026 87.5mm

.040 Over Bore Piston & Gasket Kit for Honda Rancher 420

This .040 over bore piston and gasket kit for Honda Rancher 420 delivers a precision rebuild solution for 2009-2026 models with an 87.5mm oversize piston and matched gaskets to restore engine compression and performance.

Overview

The .040 over bore piston and gasket kit for Honda Rancher 420 is designed for engine overhauls requiring a 0.040-inch oversize piston. It includes a forged piston, rings, wrist pin, and complete gasket set to refresh your ATV’s top end. This kit is intended for Honda Rancher 420 owners performing a rebuild to eliminate cylinder wear and improve power delivery.

Built For Performance

• Oversized 87.5mm piston provides tight cylinder clearance after boring
• High-strength aluminum alloy construction resists heat and stress
• Precision-machined ring grooves ensure proper oil control and compression
• Complete gasket set includes head, base, and valve cover gaskets
• Each component is engineered to match OEM specifications for a reliable fit

Fits These Machines

• for Honda Rancher 420 (2009-2026)

On-The-Job Use

• Trail riding with worn top-end restored to like-new power
• Farm or utility work requiring reliable engine performance
• Engine rebuilding after high mileage or overheating damage
• Power sports maintenance and repair shops handling Rancher 420 models

Specs At A Glance

Good To Know

Q: Is the piston pre-assembled with rings? A: Rings are included but not pre-installed; follow the manufacturer’s ring gap and orientation instructions during assembly.

Q: Do I need to have the cylinder bored to match? A: Yes, the cylinder must be professionally bored to 87.5mm and honed to accept this oversize piston for proper clearance and sealing.

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