ATHENA Piston Ring Set Ø66 mm for HONDA CRF 150 2007-2026

The ATHENA S41316180 set of piston rings (Ø 66 mm) is designed for HONDA CRF 150 from 2007 to 2026. Piston rings sit in the grooves of the piston. They seal between the piston and the cylinder, carry heat from the piston into the cylinder and, on a four-stroke, scrape oil off the cylinder walls. Once worn, they let compression leak past: the engine loses its punch.

Specifications

• Brand: ATHENA
• Manufacturer part number: S41316180
• EAN code: 8051757068210
• For ATHENA piston
• Diameter: 66 mm
• Weight: 10 g
• Engine: 4-stroke

When to replace it?

• Loss of compression and power, harder starting.
• Ring end gap, measured in the cylinder, larger than the figure in the manual.
• Ring stuck in its groove or showing traces of blow-by.
• On a four-stroke: oil consumption and blue smoke.

At every top end inspection, and at the latest when the piston is replaced. On a piston that is still within spec, new rings at mid-life bring the compression back. As a Cross-Mania guideline, the complete piston is replaced every 30 to 60 hours of engine running depending on whether you race or ride for fun.

Fitting tips

1. Clean the piston grooves (a broken old ring makes a good scraper) without widening them.
2. Place each ring in the cylinder, pushed in square with the piston, and measure its end gap with a feeler gauge.
3. Open the rings just enough to slip them over the piston, by hand or with ring pliers: opened too far, they distort or break.
4. Mark facing up, gaps staggered by about 120°, without overlapping the ends of the oil control ring.
5. Lightly oil the cylinder and the rings before reassembly, with a new top end gasket kit.

Why ATHENA?

Athena, an Italian company founded in 1973 near Vicenza, designs gaskets, pistons and cylinder kits for motorcycles. An OEM supplier to KTM, Ducati, Fantic, Piaggio and Triumph and a partner of the MXGP world championship, it develops its parts on the test bench and on the track with racing teams.

Spare parts and items to plan

• Piston : VERTEX 23304 · VERTEX 3304
• Top-end gasket kit : ATHENA S4102100062 · ATHENA S410210001285
• Piston pin : WOSSNER WP058 · WOSSNER CW14
• Piston pin clips : WISECO 125 L
• Spark plug : NGK 2306 · NGK 3797

Frequently asked questions

Which diameter should I choose?
The nominal diameter of your piston, given in the title. The rings go on a piston of the same bore size.

Does the engine need breaking in?
Yes: one hour of gentle break-in, without sustained full throttle, so the rings bed in to the cylinder.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
HONDA CRF 150 2026
HONDA CRF 150 2025
HONDA CRF 150 2024
HONDA CRF 150 2023
HONDA CRF 150 2022
HONDA CRF 150 2021
HONDA CRF 150 2020
HONDA CRF 150 2019
HONDA CRF 150 2018
HONDA CRF 150 2017
HONDA CRF 150 2016
HONDA CRF 150 2015
HONDA CRF 150 2014
HONDA CRF 150 2013
HONDA CRF 150 2012
HONDA CRF 150 2011
HONDA CRF 150 2010
HONDA CRF 150 2009
HONDA CRF 150 2008
HONDA CRF 150 2007