This oversize piston ring set is designed to restore peak top-end performance on the Honda TRX 500 Foreman family operating from 2005 through 2019. The OS 0.75 kit targets worn bore wear and ringland scoring to recapture compression, throttle response, and reduced oil consumption. Engineered to meet the original design intent, this aftermarket option offers a cost-effective path to a reliable, high-mileage top end.

Built for trail and farm use, this OS 0.75 ring set addresses common wear symptoms—loss of compression, smokey starts, and increased blow-by—without the premium OEM price tag. Expect a tighter seal, steadier power delivery, and longer service life between top-end refreshes when paired with proper teardown, bore inspection, and break-in practices. It’s a purpose-built upgrade that supports consistent performance under demanding conditions while keeping maintenance affordable.

Comprehensive Vehicle Fitment

Product Specifications

OEM & Aftermarket Cross-Reference Information

What's Included

This kit includes the essential piston ring components needed for a proper TRX 500 top-end refresh.

• Top Compression Ring
• Second Compression Ring
• Oil Control Ring

Note: Piston, piston pin, circlips, and cylinder gaskets are not included in this ring-set kit.

Why Choose This Aftermarket Replacement?

• Direct-Fit Compatibility: Specifically engineered for the Honda TRX 500 Foreman OS 0.75 bore, ensuring a straightforward install.
• OEM Cross-Reference: Cross-checked with Honda OEM part numbers for compatibility, while delivering a cost-effective aftermarket option.
• Premium Materials: Built from durable alloy/iron-grade rings with wear-resistant coatings to withstand high-load, long-life operation.
• Performance Restoration: Tight seal reduces blow-by and restores compression, delivering responsive throttle and power.
• Reliability in Demanding Conditions: Designed to endure trail and agricultural use, with resistance to heat, oil exposure, and piston-ring wear.
• Cost-Effective Alternative: Significantly lowers replacement costs compared with OEM equivalents without sacrificing essential performance.

Installation Notes:

• Before disassembly, consult the service manual for top-end procedures; ensure the cylinder bore is clean and free of scoring prior to ring installation.
• Measure the bore to confirm 92.75 mm and verify that an OS 0.75 overbore is appropriate for the piston cylinder in use.
• Inspect the piston and ring lands for wear or damage; replace any fatigued components to avoid early ring failure.
• Lubricate all rings and the piston skirt with assembly lube or clean engine oil before installation to ensure proper seating.
• Install rings in the correct orientation and with proper end-gap placement; use the appropriate ring compressor to prevent ring distortion.
• During reassembly, avoid bending or twisting rings; torque assembly points per the service manual and perform a careful break-in procedure after start-up.

Why Upgrade?

Running a worn top end with exhausted ring seals leads to consistent compression loss, increased oil consumption, and smoky starts. This OS 0.75 ring set restores sealing integrity and compression, delivering reliable power and throttle response for demanding trail or farm work.