ATHENA Cylinder Base Gasket OE thickness for KTM, HUSQVARNA and GAS GAS 2023-2027

The ATHENA cylinder base gasket is designed for KTM EXCF 250, EXCF 350, SXF 250, SXF 350, XCF 250, XCF 350, GAS GAS ECF 250, ECF 350, EXF 250, EXF 350, MCF 250, MCF 350 and HUSQVARNA FC 250, FC 350, FE 250, FE 350, FX 350 from 2023 to 2027. Fitted under the cylinder, the base gasket is more than just a seal: its thickness sets the height of the cylinder, and with it the engine's squish and compression.

Key features

• Several thicknesses available for the same bike.
• The right tool for setting squish, compression and timing, according to Athena.

Specifications

• Brand: ATHENA
• Manufacturer part numbers: S410270006133, S410270006146, S410270006147, S410270006148, S410270006149, S410270006150
• Available versions: OE: ref. S410270006133; 0.10 mm: ref. S410270006146; 0.20 mm: ref. S410270006147; 0.30 mm: ref. S410270006148; 0.50 mm: ref. S410270006149; 0.60 mm: ref. S410270006150
• Weight: 10 g
• Engine: 4-stroke

Choosing the right thickness

Measure the thickness of the old gasket with a vernier caliper and fit the same, unless you are deliberately adjusting the squish. A thicker gasket increases the squish and lowers compression; a thinner one does the opposite. After any change of thickness, check the squish with solder wire.

When to replace it?

• Oil or coolant seeping at the base of the cylinder.
• Gasket crushed or torn on removal.

Every time the cylinder is removed: a crushed base gasket can't be reused.

Fitting tips

1. Clean the crankcase face and the base of the cylinder without scratching them.
2. Fit the gasket dry, centred on the studs.
3. Tighten the cylinder in a criss-cross pattern to the manufacturer's torque.
4. If you have changed the thickness, measure the squish before refitting the cylinder head with a new head gasket.

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

• Top-end gasket kit : VERTEX · CENTAURO
• Piston : VERTEX · PROX
• Piston rings : PROX · VERTEX
• Coolant : LIQUI MOLY 1 L · TWIN AIR

Frequently asked questions

Which thickness should I choose?
The same as your original gasket, unless you are deliberately adjusting the squish. Thicknesses available: OE, 0.10 mm, 0.20 mm, 0.30 mm, 0.50 mm, 0.60 mm.

Should the other gaskets be replaced?
Yes, as soon as the cylinder is removed: a top end gasket kit includes all the gaskets that need replacing.

Compatibility

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

Fits:
GAS GAS ECF 250 2026
GAS GAS ECF 250 2025
GAS GAS ECF 250 2024
GAS GAS ECF 350 2025
GAS GAS ECF 350 2024
GAS GAS EXF 250 2025
GAS GAS EXF 250 2024
GAS GAS EXF 350 2025
GAS GAS EXF 350 2024
GAS GAS MCF 250 2026
GAS GAS MCF 250 2025
GAS GAS MCF 250 2024
GAS GAS MCF 250 2023
GAS GAS MCF 350 2025
GAS GAS MCF 350 2024
HUSQVARNA FC 250 2026
HUSQVARNA FC 250 2025
HUSQVARNA FC 250 2024
HUSQVARNA FC 250 2023
HUSQVARNA FC 350 2026
HUSQVARNA FC 350 2025
HUSQVARNA FC 350 2024
HUSQVARNA FC 350 2023
HUSQVARNA FE 250 2026
HUSQVARNA FE 250 2025
HUSQVARNA FE 250 2024
HUSQVARNA FE 350 2026
HUSQVARNA FE 350 2025
HUSQVARNA FE 350 2024
HUSQVARNA FX 350 2025
HUSQVARNA FX 350 2024
HUSQVARNA FX 350 2023
KTM EXCF 250 2027
KTM EXCF 250 2026
KTM EXCF 250 2025
KTM EXCF 250 2024
KTM EXCF 350 2027
KTM EXCF 350 2026
KTM EXCF 350 2025
KTM EXCF 350 2024
KTM SXF 250 2027
KTM SXF 250 2026
KTM SXF 250 2025
KTM SXF 250 2024
KTM SXF 250 2023
KTM SXF 350 2027
KTM SXF 350 2026
KTM SXF 350 2025
KTM SXF 350 2024
KTM SXF 350 2023
KTM XCF 250 2026
KTM XCF 250 2025
KTM XCF 250 2024
KTM XCF 250 2023
KTM XCF 350 2026
KTM XCF 350 2025
KTM XCF 350 2024
KTM XCF 350 2023