Namura Size B (46.96mm) Piston Kit Yamaha 1993-2001 YZ80 Standard Bore 47mm

Piston Kit Size B (46.96mm) for Yamaha

This Namura piston kit size B (46.96mm) is a direct replacement standard bore piston assembly for Yamaha YZ80 models from 1993 through 2001, engineered to restore compression and power in two‑stroke engines with an OEM cross‑reference to the 47mm standard bore specification.

Overview

Designed as a size B (46.96mm) standard bore piston kit for Yamaha YZ80 motorcycles, this component delivers reliable performance for riders rebuilding their top end. The kit includes a precision‑machined piston, rings, wrist pin, and circlips, ensuring a complete refresh for the 47mm bore engine. It is an ideal choice for maintaining the Yamaha YZ80′s original power output.

Built For Performance

• Manufactured from high‑silicon aluminum alloy for strength and heat dissipation
• Precision‑ground ring grooves reduce friction and improve seal
• Includes a hardened steel wrist pin with a molybdenum‑disulfide coating
• Circlips are heat‑treated for secure retention under high RPM
• Each kit is weight‑matched for balanced engine operation

Fits These Machines

• for Yamaha YZ80 (1993‑2001)

On‑The‑Job Use

• Motocross track racing requiring frequent top‑end rebuilds
• Trail riding where reliable two‑stroke performance is essential
• Competitive youth racing classes using the YZ80 platform
• Engine restoration projects for vintage Yamaha dirt bikes

Specs At A Glance

Good To Know

Q: Does this piston kit require any modifications to install? A: No, it is a direct replacement for the standard bore; simply hone the cylinder to the correct clearance and assemble using fresh gaskets.

Q: What ring end‑gap should be set for this piston? A: Follow the factory service manual for the Yamaha YZ80—typically 0.008–0.012 inch for the top ring and 0.010–0.014 inch for the second ring.

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