ATHENA Cylinder Head Gasket for YAMAHA YZ 125 and GAS GAS EC 125 1997-2015

The ATHENA P400485999003 head gasket is designed for YAMAHA YZ 125 and GAS GAS EC 125 from 1997 to 2015. The head gasket seals between the cylinder head and the cylinder: it holds in the combustion pressure and, depending on the engine, the coolant. Crushed when tightened, it can never be reused.

Specifications

• Brand: ATHENA
• Manufacturer part number: P400485999003
• EAN code: 8051764547807
• Weight: 400 g
• Engine: 2-stroke

When to replace it?

• Loss of compression, less lively engine.
• Black marks or hissing at the head/cylinder joint.
• Coolant level dropping, bubbles in the radiator.

Every time the cylinder head is removed, and therefore at every piston change.

Fitting tips

1. Clean the cylinder head and cylinder faces without scratching them.
2. Fit the gasket dry, the right way round, centred on the studs and the coolant holes.
3. No sealant on the gasket.
4. Tighten the cylinder head in a criss-cross pattern, in several stages, to the manufacturer's torque.
5. Refill the coolant and take the opportunity to replace the spark plug.

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

• ATHENA cylinder kit : ATHENA
• Piston : ATHENA S4C05400016A · ATHENA S4C04450001 · ATHENA S4C05400016B
• Piston rings : ATHENA
• Cylinder head and dome : ATHENA
• Exhaust power valve parts : ATHENA S410485303011 · ATHENA S410485303027
• Coolant : LIQUI MOLY 1 L · TWIN AIR
• Spark plug : NGK 3230 · NGK 3530

Frequently asked questions

Is the gasket enough to refit the cylinder head?
It replaces the head gasket only. If you also remove the cylinder, go for a complete top end gasket kit instead.

Compatibility

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

Fits:
GAS GAS EC 125 2015
GAS GAS EC 125 2014
GAS GAS EC 125 2013
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 125 2000
YAMAHA YZ 125 1999
YAMAHA YZ 125 1998
YAMAHA YZ 125 1997