ATHENA Oil Seal 20x40x7 mm for YAMAHA YZ 65, 85, 125, 250, FANTIC XE, XX 125, 250, 300 and KAWASAKI KX 250 2000-2027

The ATHENA 20x40x7 mm M730901120002 oil seal is designed for YAMAHA YZ 65, YZ 85, YZ 125, YZ 250, FANTIC XE 125, XE 300, XX 125, XX 250 and KAWASAKI KX 250 from 2000 to 2027. Sold by size, this oil seal replaces a worn seal on an engine, water pump, shift, kickstart or hub shaft, as long as the dimensions match. Its lip rubs on the shaft all the time: with heat and hours of use, it hardens and eventually leaks.

Specifications

• Brand: ATHENA
• Manufacturer part number: M730901120002
• EAN code: 8051757101139
• Rubber-covered outer case
• Profile: TCJ
• Engine: 2-stroke

When to replace it?

• Oil weeping or leaking around the shaft.
• Lip hardened, cracked or turned over when you take the seal out.
• A groove worn into the shaft where the lip runs: the new seal must sit on a clean, undamaged surface.
• On a two-stroke, a crankshaft seal that lets air in makes the idle unstable and leans out the mixture.

Replace an oil seal as soon as it leaks, and always whenever you remove it: once a lip has come out of its housing, it never seals properly again. Note the three dimensions marked on the old seal (for example 20 x 32 x 7) or measure the shaft, the housing and the thickness with a caliper.

Fitting tips

1. Drive out the old seal with a seal puller or a screwdriver with a protected tip, without scratching the housing or the shaft.
2. Clean the housing and check the shaft: a scratch or groove under the lip will make the new seal leak.
3. Lightly oil the lip or smear it with grease, then drive the seal in perfectly square with a socket that presses on its outer edge, lip (spring side) facing the oil.
4. Protect the lip from splines, threads or keys as the shaft goes through (adhesive tape or a thin sleeve).

Why ATHENA?

Founded in 1973 near Vicenza, Athena is an Italian engine gasket specialist that has made its gaskets on its own production lines since day one, as well as a renowned manufacturer of pistons and cylinder kits. The brand supplies original equipment to manufacturers such as KTM, Ducati, Fantic, Piaggio and Triumph, and is a partner of the MXGP motocross world championship.

Spare parts and items to plan

• Grease : MOTUL 400 g

Frequently asked questions

How do I read an oil seal size?
In this order: inner diameter, outer diameter, thickness, in millimetres. A 20 x 32 x 7 seal fits a 20 mm shaft in a 32 mm housing and is 7 mm thick.

NBR or FKM (Viton)?
NBR (nitrile rubber) suits most uses. FKM handles heat better: it's the right choice near the crankshaft or the water pump. The material is listed in the specifications when it is known.

Why would a new seal leak?
Most of the time the shaft is marked under the lip, the seal went in crooked, or the lip folded over as the shaft went through.

Compatibility

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

Fits:
FANTIC XE 125 2026
FANTIC XE 125 2025
FANTIC XE 125 2024
FANTIC XE 125 2023
FANTIC XE 125 2022
FANTIC XE 125 2021
FANTIC XE 300 2026
FANTIC XE 300 2025
FANTIC XE 300 2024
FANTIC XX 125 2026
FANTIC XX 125 2025
FANTIC XX 125 2024
FANTIC XX 125 2023
FANTIC XX 125 2022
FANTIC XX 125 2021
FANTIC XX 250 2026
FANTIC XX 250 2025
FANTIC XX 250 2024
FANTIC XX 250 2023
FANTIC XX 250 2022
KAWASAKI KX 250 2002
KAWASAKI KX 250 2001
YAMAHA YZ 65 2027
YAMAHA YZ 65 2026
YAMAHA YZ 65 2025
YAMAHA YZ 65 2024
YAMAHA YZ 65 2023
YAMAHA YZ 65 2022
YAMAHA YZ 65 2021
YAMAHA YZ 65 2020
YAMAHA YZ 65 2019
YAMAHA YZ 65 2018
YAMAHA YZ 85 2027
YAMAHA YZ 85 2026
YAMAHA YZ 85 2025
YAMAHA YZ 85 2024
YAMAHA YZ 85 2023
YAMAHA YZ 85 2022
YAMAHA YZ 85 2021
YAMAHA YZ 85 2020
YAMAHA YZ 85 2019
YAMAHA YZ 125 2027
YAMAHA YZ 125 2026
YAMAHA YZ 125 2025
YAMAHA YZ 125 2024
YAMAHA YZ 125 2023
YAMAHA YZ 125 2022
YAMAHA YZ 125 2021
YAMAHA YZ 125 2020
YAMAHA YZ 125 2019
YAMAHA YZ 125 2018
YAMAHA YZ 125 2017
YAMAHA YZ 125 2016
YAMAHA YZ 125 2015
YAMAHA YZ 125 2014
YAMAHA YZ 125 2013
YAMAHA YZ 125 2012
YAMAHA YZ 125 2011
YAMAHA YZ 125 2010
YAMAHA YZ 125 2009
YAMAHA YZ 125 2008
YAMAHA YZ 125 2007
YAMAHA YZ 125 2006
YAMAHA YZ 125 2005
YAMAHA YZ 125 2004
YAMAHA YZ 125 2003
YAMAHA YZ 125 2002
YAMAHA YZ 125 2001
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