ATHENA Cylinder Base Gasket for SHERCO SE 250, SE 300 2019-2025

The ATHENA cylinder base gasket is designed for SHERCO SE 250, SE 300 from 2019 to 2025. The base gasket seals between the cylinder and the crankcase. Its thickness matters: it sets the height of the cylinder, and therefore the squish, the compression and, on a two-stroke, the port timing.

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: S410462006024, S410462006028, S410462006027, S410462006029, S410462006026, S410462006030, S410462006025
• Available versions: OE: ref. S410462006024; 0.10 mm: ref. S410462006028; 0.30 mm: ref. S410462006027; 0.40 mm: ref. S410462006029; 0.50 mm: ref. S410462006026; 0.60 mm: ref. S410462006030; 0.75 mm: ref. S410462006025
• Weight: 40 g
• Engine: 2-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?

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 M752007700085 · ATHENA M752010700004
• Piston : ATHENA · METEOR
• Piston rings : WOSSNER · VERTEX
• Coolant : MOTUL 1 L · MOTUL 20 L

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, 0.30 mm, 0.40 mm, 0.50 mm, 0.60 mm, 0.75 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:
SHERCO SE 250 2025
SHERCO SE 250 2024
SHERCO SE 250 2023
SHERCO SE 250 2022
SHERCO SE 250 2021
SHERCO SE 250 2020
SHERCO SE 250 2019
SHERCO SE 300 2025
SHERCO SE 300 2024
SHERCO SE 300 2023
SHERCO SE 300 2022
SHERCO SE 300 2021
SHERCO SE 300 2020
SHERCO SE 300 2019