Restore compression and sealing in your TRX 350 engine with the OS 0.25 piston ring kit, engineered for 2000–2006 FM, TM, FE, and TE variants. This complete aftermarket set targets tired rings to reclaim power, reduce blow-by, and improve overall sealing without the higher price of OEM parts. The oversize 0.25 mm rings are designed to recondition worn bores and ring lands, delivering dependable performance for trail and farm use. Built to fit the TRX 350 lineage, this kit helps restore steady compression and smooth operation after years of hard use.

This aftermarket replacement offers a precise OS 0.25 fit, enabling renewed compression on engines with worn cylinder walls and ring lands without a full top-end rebuild. The three-piece configuration tackles the top compression ring, second compression ring, and oil ring to restore sealing, minimize oil consumption, and reduce blow-by. It’s a reliable, field-ready choice for riders and farmers who demand durable restoration that won’t break the bank.

Comprehensive Vehicle Fitment

Product Specifications

OEM & Aftermarket Cross-Reference Information

What's Included

In the box you’ll find the following three-ring set designed for the TRX 350 OS 0.25 kit:

• Top Compression Ring
• Second Compression Ring
• Oil Ring

• Note: Piston, wrist pin, and circlips are not included. Related gaskets or seals are not included.

Why Choose This Aftermarket Replacement?

• Direct-Fit Compatibility: Precisely designed to match Honda TRX 350 FM/TM/FE/TE models from 2000–2006.
• OEM Cross-Reference: Clear cross-reference to Honda OEM numbers (13011-HN5-671/672) with robust aftermarket alternatives available.
• OS 0.25 Precision: Oversize rings restore compression on worn bores without a full top-end rebuild.
• Premium Materials & Build: Engineered to OEM-replacement standards for reliable wear resistance.
• Performance Restoration: Reclaims power, compression, and oil retention for trail and farm use.
• Value for Money: A cost-effective option that keeps the TRX 350 on the trail without OEM premium pricing.

Installation Notes:

• Thoroughly clean the cylinder bore and remove glazing or scoring before installation.
• Inspect bore diameter and measure ring end gaps with a feeler gauge after re-bore/honing to confirm suitability for OS 0.25 rings.
• Lubricate rings and cylinder walls with clean engine oil or assembly lube prior to installation.
• Orient the rings correctly: align the markings on top and second rings as indicated by the manufacturers’ installation guides; stagger the end gaps around the circumference to avoid all gaps aligning.
• Use a proper ring compressor when installing the piston to prevent ring deformation or snagging on the bore.
• After assembly, perform a careful break-in procedure (light throttle and steady RPM) and check for oil leaks or abnormal blow-by during initial startup.

Why Upgrade?

Running a worn piston ring set for a TRX 350 can lead to reduced compression, higher oil consumption, and excess blow-by, which quickly erodes performance. Replacing with an OS 0.25 piston ring kit restores sealing, improves power delivery, and revives reliable compression for rugged trail or farm use.