Piston Ring Sets for Yanmar & Kubota Diesel Engines

Sensei stocks ring sets for 40+ Yanmar and Kubota engine models. Compression rings, oil control rings, expanders full set, one part number. OEM cross-reference on every listing.

What Is a Piston Ring Set?

The rings on a piston do two jobs: seal and scrape. Compression rings hold combustion pressure against the cylinder wall. The oil ring scrapes the excess back into the sump and leaves a controlled film behind. A piston typically carries two compression rings and one oil ring with an expander. Multiply that by the number of cylinders and you have your full set.

When rings wear out, blow-by goes up, oil consumption goes up, compression comes down. It's not subtle. A ring replacement at overhaul time gets you back to spec.

How to Choose the Right Piston Ring Set for Your Engine

Engine model number first. On Yanmar it's on the valve cover or block 4TNV98, 3TNV88, 3TNE68 are the common ones. Kubota: V2403, D1803, D902.

From there, bore condition matters. Cylinders worn and bored out? You need oversize rings: 0.25 mm, 0.50 mm, or 0.75 mm over are the standard increments. Fresh hone or factory-spec bore? Standard rings.

If you've got an OEM number from a service manual or a previous order, use it. Every Sensei listing cross-references the OEM number so you can check fitment before you buy.

Yanmar & Kubota Piston Ring Set Catalog

Yanmar Piston Ring Sets by Engine Model

TNV and TNE series are fully covered: 4TNV98, 3TNV88, 4TNV84, 3TNE68, 4TNE98, 4TNV106. Marine engines are listed separately 3YM30, 4JH, 6LY, 6LP. Each listing shows the engine model, standard or oversize, and the OEM numbers replaced.

Kubota Piston Ring Sets by Engine Model

V2403, D1803, V3800, Z482, D902, V2607, V1305, V2203, D1105, D722, Z602. These run in compact excavators, utility tractors, generators, forklifts. Same ring set regardless of application equipment compatibility is noted on each listing for reference.

Piston Ring Sets by Application

Marine Yanmar engines — 3YM30, 4JH, 6LY — sit in saltwater environments and often go long periods without running. Ring condition matters more here than on a construction engine that turns over every day.

The 4TNV98 and V2403 are the workhorses in mini excavators and skid steers. High cycle counts, regular overhaul intervals. Generator sets frequently use the same blocks if the base engine matches, the ring set does too.

OEM & Aftermarket Piston Ring Set Solutions with Global Support

Genuine Yanmar ring sets are stocked alongside aftermarket alternatives for the same models. Genuine parts carry original OEM numbers, direct fitment. Aftermarket sets are built to the same bore tolerances and cost less the right call for a standard rebuild when you don't need the OEM box.

Orders ship to 90+ countries. Çözüm Makina has been sourcing Yanmar and Kubota parts for 30 years; this catalog is built on that. Technicians, service shops, and distributors order direct. Wholesale pricing and B2B terms are available through the distributor inquiry form.