Namura .040 Over Bore Piston Kit for Honda Sportrax 250 TRX250EX TRX250X 69.5mm

Namura .040 Over Bore Piston Kit for Honda Sportrax 250 TRX250EX TRX250X

This Namura .040 over bore piston kit is a direct replacement piston assembly for Honda Sportrax 250 models, increasing engine displacement to 69.5mm for added power and torque.

Overview

The Namura .040 over bore piston kit is designed for Honda Sportrax 250 TRX250EX and TRX250X ATVs, providing a cost-effective way to restore or enhance engine performance. This kit includes a precision-cast piston, rings, and wrist pin for a complete top-end rebuild. Ideal for riders seeking reliable power gains from their 250cc engine.

Built For Performance

• Precision-machined from high-strength aluminum alloy for durability and heat resistance
• .040 over bore size increases displacement by approximately 2cc for noticeable power gain
• Includes moly-coated rings for reduced friction and improved sealing
• Forged wrist pin with retaining clips ensures secure connection to connecting rod
• Manufactured to exacting tolerances for easy installation and long service life

Fits These Machines

• for Honda Sportrax 250 TRX250EX
• for Honda Sportrax 250 TRX250X

On-The-Job Use

• Used for rebuilding top end of Honda Sportrax 250 engines after wear or damage
• Ideal for restoring compression and power in high-mileage ATVs
• Commonly installed during performance upgrades or after bore damage
• Provides reliable operation for trail riding, recreational use, and light racing

Specs At A Glance

Good To Know

Q: Will this piston kit require cylinder boring? A: Yes, because it is an over bore piston, the cylinder must be bored to the matching 69.5mm diameter for proper fit.

Q: Can this kit be used with stock cylinder head? A: Yes, the stock cylinder head is compatible, but always check valve-to-piston clearance after installation.

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