ATHENA O-Ring Ø74.00x2 mm for YAMAHA YZ 250, KTM EXC 250, MXC 250, SX 250 and FANTIC XX 250 1990-2026

The ATHENA Ø74.00x2 mm M752007400074 O-ring is designed for KTM EXC 250, MXC 250, SX 250, YAMAHA YZ 250 and FANTIC XX 250 from 1990 to 2026. An O-ring is a rubber ring with a round cross-section, squeezed into a groove between two parts to seal them. It is defined by its inner diameter and its cross-section thickness, in millimetres. On a bike you'll find them everywhere: drain plugs, covers, radiator fittings, water pump, oil filter, suspension.

Specifications

• Brand: ATHENA
• Manufacturer part number: M752007400074
• EAN code: 8051757188574
• Material: silicone
• Hardness: 70 Shore A
• Engine: 2-stroke

When to replace it?

• Oil, coolant or fuel weeping at a plug, cover or fitting.
• O-ring flattened, hardened, split or pinched when you take it out.
• O-ring swollen or softened after contact with a fluid it isn't suited to.

Change the O-ring every time you remove the part it seals: it costs a few cents, next to the price of a leak. Measure the inner diameter and cross-section thickness of the old ring with a caliper, without squashing it, or use the size given in the workshop manual.

Fitting tips

1. Clean the groove and the mating surface: a grain of sand or a scrap of old seal is enough to cause a leak.
2. Lightly oil the new O-ring, or coat it with a compatible grease, so it seats without twisting.
3. Lay it in the bottom of its groove without rolling it or stretching it more than necessary, then bring the parts together squarely.
4. Tighten to the torque in the manual: an O-ring seals through controlled compression, not maximum tightening.

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

• Grease : MOTUL 400 g

Frequently asked questions

How do I measure an O-ring?
Two dimensions are enough: the inner diameter and the cross-section thickness (the diameter of the rubber “cord”). Measure without squashing the ring, or take the dimensions of the groove.

Can I reuse an O-ring?
It's not recommended: squeezed into its groove, it has taken on its shape and hardened. At this price, always fit a new one.

Which material?
NBR handles oil and fuel; FKM (Viton) stands up better to heat. The material is listed in the specifications when it is known.

Compatibility

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

Fits:
FANTIC XX 250 2023
FANTIC XX 250 2022
KTM EXC 250 2004
KTM MXC 250 2003
KTM MXC 250 2002
KTM SX 250 2004
KTM SX 250 2003
KTM SX 250 2002
KTM SX 250 2001
KTM SX 250 2000
KTM SX 250 1999
KTM SX 250 1998
KTM SX 250 1997
KTM SX 250 1996
KTM SX 250 1995
KTM SX 250 1994
KTM SX 250 1993
KTM SX 250 1992
KTM SX 250 1991
KTM SX 250 1990
YAMAHA YZ 250 2026
YAMAHA YZ 250 2025
YAMAHA YZ 250 2024
YAMAHA YZ 250 2023
YAMAHA YZ 250 2022
YAMAHA YZ 250 2021
YAMAHA YZ 250 2020
YAMAHA YZ 250 2019
YAMAHA YZ 250 2018
YAMAHA YZ 250 2017
YAMAHA YZ 250 2016
YAMAHA YZ 250 2015
YAMAHA YZ 250 2014
YAMAHA YZ 250 2013
YAMAHA YZ 250 2012
YAMAHA YZ 250 2011
YAMAHA YZ 250 2010
YAMAHA YZ 250 2009
YAMAHA YZ 250 2008
YAMAHA YZ 250 2007
YAMAHA YZ 250 2006
YAMAHA YZ 250 2005
YAMAHA YZ 250 2004
YAMAHA YZ 250 2003
YAMAHA YZ 250 2002
YAMAHA YZ 250 2001
YAMAHA YZ 250 2000
YAMAHA YZ 250 1999