ATHENA Piston Ring Set Ø90 mm for KTM EXCF 350, SXF 350 and HUSQVARNA FC 350, FE 350 2011-2015

The ATHENA S41316222 set of piston rings (Ø 90 mm) is designed for KTM EXCF 350, SXF 350 and HUSQVARNA FC 350, FE 350 from 2011 to 2015. 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: S41316222
• EAN code: 8050043262813
• For ATHENA piston
• Diameter: 90 mm
• Weight: 20 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 : WOSSNER · PROX
• Top-end gasket kit : CENTAURO
• Piston pin : VERTEX · WOSSNER
• Piston pin clips : WISECO · WOSSNER
• Spark plug : NGK

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:
HUSQVARNA FC 350 2015
HUSQVARNA FC 350 2014
HUSQVARNA FE 350 2015
HUSQVARNA FE 350 2014
KTM EXCF 350 2015
KTM EXCF 350 2014
KTM EXCF 350 2013
KTM EXCF 350 2012
KTM SXF 350 2015
KTM SXF 350 2014
KTM SXF 350 2013
KTM SXF 350 2012
KTM SXF 350 2011