ATHENA Cylinder Head Gasket for KTM GS 125, MX 125 1984-1986

The ATHENA S410270001005 head gasket is designed for KTM GS 125, MX 125 from 1984 to 1986. 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: S410270001005
• EAN code: 8051757102570
• Thickness: OE
• Weight: 50 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

• Top-end gasket kit : ATHENA P400270600014 · ATHENA S410270001006
• Piston : VERTEX · WOSSNER
• Coolant : LIQUI MOLY 1 L · TWIN AIR
• Spark plug : see the selection

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:
KTM GS 125 1986
KTM GS 125 1985
KTM GS 125 1984
KTM MX 125 1986
KTM MX 125 1985
KTM MX 125 1984