Piston Rings (Std / 0.5 mm / 1.0 mm OS) | Honda CT90 / Trail 90

Your Price: $30.00

CMC Part Number:U4334

Replaces OEM Part:13011-121-762, 13010-028-020, 13010-028-025, 13010-028-035, 13010-121-732, 130D1-121-762, 130C1-121-762, 130B1-121-762, 130A1-121-762, 13020-028-020, 13020-028-025, 13020-028-035, 13030-028-000, 13030-028-020, 13030-028-025, 13030-028-035, 13030-121-732, 13031-028-005, 13031-102-732, 13031-102-733, 13040-028-000, 13040-028-020, 13040-028-025, 13040-028-035, 13040-121-732, 13050-028-000, 13050-028-020, 13050-028-025, 13050-028-035, 13050-121-732
Qty:Sold Individually

Select Piston Ring Size:

Standard - 49 mm (#4335)

0.5 mm Oversize (#4336)

1.00 mm Oversize (#4337)

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Description
Customer Reviews
Compatibility Chart

Compatibility List

Part

Piston rings (Std / 0.5 mm / 1.0 mm) for Honda CT90 - "Trail 90" Motorcycles

Why You Need This

Every engine eventually reaches a point where a top-end overhaul becomes necessary - and your vintage Honda Trail 90 is no exception. Fortunately, in many cases a simple hone and a fresh set of standard-size piston rings are all that is needed to bring performance back to life. However, if your cylinder bore is at or beyond the factory service limit, a full rebore will be required. That means stepping up to oversize pistons, matching oversize rings and a new wrist pin with fresh retaining clips.

No matter which route your CT90 K0-K8 or CT90 1978 - 1979 needs, we've got you covered. Our modern piston rings are designed for improved sealing, easy installation and long lasting durability, so your Trail 90 runs like new for years to come.

Piston Ring kits are offered in three different sizes for the Honda 90cc family of engines:

Standard (49 mm bore) - #4335
0.5 mm Over Size - #4336
1.0 mm Over Size - #4337

Our standard piston ring kits are designed to fit the factory Honda pistons in standard size (49 mm) used in the Honda Trail 90 engines.

Oversize piston ring kits are available in 0.5 mm and 1.00 mm oversize, designed to fit factory Honda oversize pistons as well as our very own "Pulsar" series oversize pistons.

Our modern piston rings are designed to improve sealing, ease of installation and ensure long service life.

Each piston ring set includes:

A gas nitride coated forged steel top ring (silver). This is a hard coating on all surfaces of the ring which gives it increased wear resistance and a lower coefficient of friction on the cylinder walls.
Steel phosphate 2nd ring (black).
An easy-to-install modern nitride three piece oil ring, which makes installation onto the piston and cylinder assembly A LOT easier than the old style brittle cast iron one piece oil rings.

We suggest getting a fresh set of piston pins and clips along with an overhaul gasket kit to get the rebuild done right.

Installation Tip

The cylinder must be measured and checked for taper, roundness and top ridge. To complete this, you will need a micrometer and either the telescoping gauges or dial bore gauge. If everything measures out then the cylinders must be cleaned up with a cylinder hone to accept new rings. We always recommend to double check your measurement work. Oil everything well upon assembly. Top ring has a silver face. Top and second rings are installed with the "R" marking on the rings facing up towards the crown of the piston. Oil ring is installed with the wavy spacer first and then thin rail on the top and bottom of the wavy. It makes a sandwich. Face the top two rings gaps 180 degrees from each other and the oil ring openings 120 degrees apart.