Namura Standard Bore Size C Top End Kit for Honda CRF250R fits 2016-2017 76.8mm

Namura Standard Bore Size C Top End Kit for Honda

This top end kit from Namura is a direct replacement cylinder and piston assembly designed to restore compression and power in Honda CRF250R engines from 2016-2017. Featuring a 76.8mm bore size (Standard C), it provides a reliable OEM-style fit and performance for high-revving four-stroke motocross engines. Whether rebuilding or upgrading, this top end kit ensures consistent power delivery and longevity.

Overview

The Namura Standard Bore Size C Top End Kit is a complete cylinder and piston package built for the 2016-2017 Honda CRF250R. It includes a cast piston, rings, wrist pin, circlips, and cylinder assembly, delivering everything needed for a top-end overhaul. This top end kit is ideal for riders seeking a direct replacement that maintains the factory bore size of 76.8mm without the need for boring or honing.

Built For Performance

• Cast piston with precision-machined ring grooves for optimal sealing
• Heat-treated cylinder sleeve resists wear and maintains consistent clearance
• Includes wrist pin and circlips for secure installation
• Designed to match OEM compression ratio and power characteristics
• Drop-in replacement - no additional machining required

Fits These Machines

• for Honda CRF250R (2016-2017)

On-The-Job Use

• Motocross racing and track days
• Trail riding and enduro competitions
• Engine rebuilds and performance restoration

Specs At A Glance

Good To Know

Q: Does this top end kit require re-sleeving? A: No, the cylinder is supplied with a pre-installed sleeve matched to the bore size, so installation is a direct swap after cleaning the crankcase.

Q: What is the recommended break-in procedure for this piston? A: Follow standard engine break-in: a few heat cycles with varying RPM, avoiding sustained high loads for the first hour of operation.

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