Restore peak compression and sealing with this standard-rings piston ring kit designed for a popular four-wheel-drive ATV platform spanning model years 1995 through 2003. The set is engineered to replace worn rings with factory-geometry parts, delivering crisp throttle response, improved fuel economy, and reliable starting while staying true to original performance characteristics. If you’re seeing power fade, blue smoke on startup, or elevated oil consumption, this kit helps bring the engine back to its intended feel and efficiency without requiring a full teardown or modification.

This aftermarket replacement focuses on delivering a durable, cost-effective solution that restores proper ring seal and oil control. Built to handle rugged trail riding and farm work, it’s designed to endure heat and wear while maintaining consistent compression under load, helping you get back to reliable operation without the premium OEM price tag.

Comprehensive Vehicle Fitment

Note: Compatibility is based on OEM references for this engine family (13011-HM7-003 / 13011-HM7-004) and widely used aftermarket cross-reference data for the TRX400FW/TRX400FM platforms.

Product Specifications

OEM & Aftermarket Cross-Reference Information

What's Included

In the box, you’ll find the essential piston-ring components for a single piston rebuild:

• Top Compression Ring
• Second Compression Ring
• Oil Ring
• Oil Ring Spacer

Related parts not included: piston assembly, circlips, piston pin, and gaskets.

Why Choose This Aftermarket Replacement?

• Direct-Fit Compatibility: Precisely matched to the TRX 400FW/FM engines from 1995–2003 for hassle-free installation.
• OEM Cross-Reference: Aligns with OEM references 13011-HM7-003 and 13011-HM7-004 to ensure parity with factory specifications.
• Premium Materials & Original Geometry: Engineered to mirror the original seal and wear characteristics, helping restore peak performance and longevity.
• Performance Restoration: Rebuilds compression and oil control to reclaim throttle response, power delivery, and fuel efficiency.
• Cost-Effective Alternative: A reliable aftermarket option that delivers dependable results without OEM-level pricing.
• Quality Assurance: Manufactured with consistent process controls to deliver repeatable fit and function across batches.

Installation Notes:

• Cleanliness first: thoroughly hone or scrub the cylinder bore, remove all debris, and verify a true, smooth surface before installing rings.
• Check end-gap and ring orientation: verify gaps against the service manual’s specifications and ensure the gaps are offset between rings when installed.
• Lubricate rings and pistons: apply clean engine oil to the rings and piston skirts to reduce initial wear during startup.
• Proper ring orientation: ensure each ring is installed with the correct side facing the correct direction to maintain seal and oil control.
• Block and bore cleanliness: wipe the bore with lint-free solvent and inspect for scratches or burrs that could compromise sealing.
• During final assembly, avoid bending or twisting rings; install them gently and verify seating with a light hand pressure before final torques.

Why Upgrade?

Running a worn piston ring set can allow compression loss, increased oil consumption, and smoky startup symptoms, all of which degrade throttle response and reliability. This replacement restores the engine’s original sealing integrity, helping maintain steady compression under load and return the ATV to dependable, efficient operation.