ATHENA Cylinder Base Gasket ref. S4102700061 for KTM, HUSQVARNA and GAS GAS 2023-2027

ATHENA offers this cylinder base gasket for KTM, HUSQVARNA and GAS GAS 2023-2027. The base gasket sits under the cylinder, on the crankcase. Crushed when tightened, it cannot be reused: replace it every time the cylinder comes off.

Why does the thickness matter?

The benefits:

• The OE thickness keeps the cylinder height intended by the manufacturer.
• Another thickness lets you correct piston-to-head clearance after machining or adjust the port timing of a 2-stroke.
• A new gasket keeps the bottom end sealed against oil and gases.

Why choose ATHENA?

Athena, founded in 1973 by Giovanni Mancassola near Vicenza and based in Alonte (Italy), designs gaskets, pistons and cylinder kits; it supplies original equipment to manufacturers such as KTM, Ducati, Fantic and Triumph.

When should you replace the base gasket on your HUSQVARNA TC 250?

Every time the cylinder comes off: piston change, top-end rebuild or cylinder inspection. Oil or mixture seeping at the base of the cylinder also points to a tired gasket.

No manufacturer figure in hours for this model. Cross-Mania guideline: compression check every 20 h of hard use and every 40 h of leisure riding.

Specifications and fitting tips

• Manufacturer part numbers: S410270006140 (0.05 mm), S410270006134 (0.20 mm), S410270006135 (0.30 mm), S410270006136 (0.40 mm), S410270006137 (0.50 mm), S410270006138 (0.70 mm), S410270006139 (0.80 mm)

Choose the thickness from the list. "OE" is the factory thickness; another thickness is used to set the cylinder height after a rebuild (piston-to-head clearance, port timing on a 2-stroke).

Cross-Mania tip: Choose the OE thickness if the cylinder and head have not been machined; if in doubt, measure the squish with solder wire before final assembly.

Spare parts and items to plan

• Top-end gasket kit : ATHENA M752007300094 · ATHENA M751802450094
• Piston : PROX · WOSSNER
• Piston rings : ATHENA · VERTEX
• Coolant : LIQUI MOLY 1 L · TWIN AIR

Compatibility

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

Fits:
GAS GAS EC 250 2025
GAS GAS EC 250 2024
GAS GAS EC 300 2027
GAS GAS EC 300 2026
GAS GAS EC 300 2025
GAS GAS EC 300 2024
GAS GAS EX 250 2025
GAS GAS EX 250 2024
GAS GAS EX 300 2027
GAS GAS EX 300 2026
GAS GAS EX 300 2025
GAS GAS EX 300 2024
GAS GAS MC 250 2026
GAS GAS MC 250 2025
GAS GAS MC 250 2024
GAS GAS MC 300 2025
HUSQVARNA TC 250 2027
HUSQVARNA TC 250 2026
HUSQVARNA TC 250 2025
HUSQVARNA TC 250 2024
HUSQVARNA TC 250 2023
HUSQVARNA TC 300 2027
HUSQVARNA TC 300 2026
HUSQVARNA TC 300 2025
HUSQVARNA TC 300 2024
HUSQVARNA TC 300 2023
HUSQVARNA TE 250 2027
HUSQVARNA TE 250 2026
HUSQVARNA TE 250 2025
HUSQVARNA TE 250 2024
HUSQVARNA TE 300 2027
HUSQVARNA TE 300 2026
HUSQVARNA TE 300 2025
HUSQVARNA TE 300 2024
HUSQVARNA TX 300 2027
HUSQVARNA TX 300 2026
HUSQVARNA TX 300 2025
HUSQVARNA TX 300 2024
HUSQVARNA TX 300 2023
KTM EXC 250 2026
KTM EXC 250 2025
KTM EXC 250 2024
KTM EXC 300 2027
KTM EXC 300 2026
KTM EXC 300 2025
KTM EXC 300 2024
KTM SX 250 2027
KTM SX 250 2026
KTM SX 250 2025
KTM SX 250 2024
KTM SX 250 2023
KTM SX 300 2027
KTM SX 300 2026
KTM SX 300 2025
KTM SX 300 2024
KTM SX 300 2023
KTM XC 250 2027
KTM XC 250 2026
KTM XC 250 2025
KTM XC 250 2024
KTM XC 250 2023
KTM XC 300 2027
KTM XC 300 2026
KTM XC 300 2025
KTM XC 300 2024
KTM XC 300 2023
KTM XCW 250 2027
KTM XCW 250 2026
KTM XCW 250 2025
KTM XCW 250 2024
KTM XCW 300 2027
KTM XCW 300 2026
KTM XCW 300 2025
KTM XCW 300 2024