ATHENA Crankshaft Bearing and Seal Kit for YAMAHA YZ 250 and FANTIC XE 300, XX 250 2001-2027

On FANTIC XE 300, XX 250 and YAMAHA YZ 250 from 2001 to 2027, the ATHENA P400485444038 crankshaft bearing and seal kit fits in place of the original part. When you rebuild a bottom end, the crankshaft bearings and oil seals are replaced together. This kit groups them under one part number.

Specifications

• Brand: ATHENA
• Manufacturer part number: P400485444038
• EAN code: 8051764546268
• Weight: 690 g
• Engine: 2-stroke

When to replace it?

• Rumbling that changes with the revs, unusual vibration.
• Radial or side play in the crankshaft.
• Leak at the crankshaft oil seals.

Every time the connecting rod or crankshaft is replaced, and at the intervals in the service manual.

Fitting tips

1. Heat the crankcase halves (around 100 to 120 °C) to remove and fit the bearings without force; put the new bearings in the freezer to help them go in.
2. Never hit the outer race of a bearing mounted on the shaft, or the inner race of a bearing mounted in the crankcase.
3. Fit the oil seals perfectly square, with greased lips.
4. Close up with a complete engine gasket kit and check that the crankshaft turns freely.
5. Take the opportunity to check the gearbox bearings and refill with fresh oil.

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

• Complete engine gasket kit : MOOSE · PROX
• Gearbox bearings : HOT RODS
• Connecting rod kit : ATHENA PB322027 · ATHENA P40321019
• Gearbox oil : LIQUI MOLY 10W30 1 L · LIQUI MOLY 80W 500 ml

Frequently asked questions

Are the oil seals included?
Yes: the kit contains the crankshaft bearings and oil seals.

What should I replace at the same time?
The complete engine gasket kit and, if the engine has some hours on it, the connecting rod.

Compatibility

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

Fits:
FANTIC XE 300 2026
FANTIC XE 300 2025
FANTIC XE 300 2024
FANTIC XX 250 2026
FANTIC XX 250 2025
FANTIC XX 250 2024
FANTIC XX 250 2023
FANTIC XX 250 2022
YAMAHA YZ 250 2027
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