ATHENA Cylinder Base Gasket for KTM SX 50, SX 65, XC 65, HUSQVARNA TC 50, TC 65 and GAS GAS MC 50, MC 65 2009-2023

ATHENA offers this cylinder base gasket for KTM SX 50, SX 65, XC 65, HUSQVARNA TC 50, TC 65 and GAS GAS MC 50, MC 65 2009-2023. 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 KTM SX 50?

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 15 h of hard use and every 30 h of leisure riding.

Specifications and fitting tips

• Manufacturer part numbers: S410270006076 (0.20 mm), S410270006097 (0.30 mm), S410270006077 (0.40 mm), S410270006078 (0.50 mm), S410270006079 (0.60 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 · PROX
• Piston : VERTEX · PROX
• Piston rings : VERTEX · WOSSNER
• 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 MC 50 2023
GAS GAS MC 50 2022
GAS GAS MC 50 2021
GAS GAS MC 65 2023
GAS GAS MC 65 2022
GAS GAS MC 65 2021
HUSQVARNA TC 50 2023
HUSQVARNA TC 50 2022
HUSQVARNA TC 50 2021
HUSQVARNA TC 50 2020
HUSQVARNA TC 50 2019
HUSQVARNA TC 50 2018
HUSQVARNA TC 50 2017
HUSQVARNA TC 65 2023
HUSQVARNA TC 65 2022
HUSQVARNA TC 65 2021
HUSQVARNA TC 65 2020
HUSQVARNA TC 65 2019
HUSQVARNA TC 65 2017
KTM SX 50 2023
KTM SX 50 2022
KTM SX 50 2021
KTM SX 50 2020
KTM SX 50 2019
KTM SX 50 2018
KTM SX 50 2017
KTM SX 50 2016
KTM SX 50 2015
KTM SX 50 2014
KTM SX 50 2013
KTM SX 50 2012
KTM SX 50 2011
KTM SX 50 2010
KTM SX 50 2009
KTM SX 65 2023
KTM SX 65 2022
KTM SX 65 2021
KTM SX 65 2020
KTM SX 65 2019
KTM SX 65 2018
KTM SX 65 2017
KTM SX 65 2016
KTM SX 65 2015
KTM SX 65 2014
KTM SX 65 2013
KTM SX 65 2012
KTM SX 65 2011
KTM SX 65 2010
KTM SX 65 2009
KTM XC 65 2010
KTM XC 65 2009