Namura .020 Over Bore Piston Kit for Honda Rancher 420 fits 2007-2026 87mm

Namura .020 Over Bore Piston Kit for Honda Rancher 420

This oversize piston kit from Namura replaces the stock piston on Honda Rancher 420 engines, boosting displacement and restoring compression with a .020 over bore (87mm) design.

Overview

The Namura .020 Over Bore Piston Kit is a direct-fit replacement for 2007-2026 Honda Rancher 420 ATVs, providing a precise 87mm piston with matching rings and pin. This piston kit enables engine rebuilding with a slightly larger bore to refresh worn cylinders.

Built For Performance

• .020 oversize (87mm) increases displacement and compression
• High-silicon aluminum alloy for thermal stability and reduced expansion
• Full floating piston pin design reduces friction
• Includes piston rings, pin, and circlips for complete installation
• Precision-machined skirt profile reduces slap and noise

Fits These Machines

• for Honda Rancher 420 2007-2026

On-The-Job Use

• Rebuilding worn or damaged engines in Honda Rancher 420 ATVs
• Performance restoration for farm and utility use
• Overbore cylinder surfacing resulting from scoring or taper
• Trail and recreational riding with increased power output

Specs At A Glance

Good To Know

Q: Do I need to recondition the cylinder before installing this piston? A: Yes, the cylinder must be professionally honed or bored to 87mm to ensure proper piston-to-wall clearance.

Q: Can this piston be used with the stock head and valves? A: Yes, the .020 over bore does not alter the cylinder head or valve clearance, so stock components are compatible.

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