ATHENA Cylinder Base Gasket for KTM EGS, EXC, GS, MX, MXC, SX 250, 300, 360, 380 1990-2003

ATHENA offers this cylinder base gasket for KTM EGS, EXC, GS, MX, MXC, SX 250, 300, 360, 380 1990-2003. 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 EXC 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: S410270006044/1 (0.20 mm), S410270006058 (0.40 mm), S410270006045/1 (0.50 mm), S410270006059 (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 M752010500094
• Piston : ATHENA · PROX
• Piston rings : VERTEX · ATHENA
• Coolant : LIQUI MOLY 1 L · TWIN AIR

Compatibility

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

Fits:
KTM EGS 250 1998
KTM EGS 250 1997
KTM EGS 250 1996
KTM EGS 250 1995
KTM EGS 250 1994
KTM EGS 250 1993
KTM EGS 250 1992
KTM EGS 250 1991
KTM EGS 250 1990
KTM EGS 300 1998
KTM EGS 300 1997
KTM EGS 300 1996
KTM EGS 300 1995
KTM EGS 300 1994
KTM EGS 300 1993
KTM EGS 300 1992
KTM EGS 300 1991
KTM EGS 300 1990
KTM EGS 360 1997
KTM EGS 360 1995
KTM EGS 380 1998
KTM EXC 250 2003
KTM EXC 250 2002
KTM EXC 250 2001
KTM EXC 250 2000
KTM EXC 250 1999
KTM EXC 250 1998
KTM EXC 250 1997
KTM EXC 250 1996
KTM EXC 250 1995
KTM EXC 250 1994
KTM EXC 250 1993
KTM EXC 250 1992
KTM EXC 250 1991
KTM EXC 250 1990
KTM EXC 300 2003
KTM EXC 300 2002
KTM EXC 300 2001
KTM EXC 300 2000
KTM EXC 300 1999
KTM EXC 300 1998
KTM EXC 300 1997
KTM EXC 300 1996
KTM EXC 300 1995
KTM EXC 300 1994
KTM EXC 300 1993
KTM EXC 300 1992
KTM EXC 300 1991
KTM EXC 300 1990
KTM EXC 360 1997
KTM EXC 360 1995
KTM EXC 380 2003
KTM EXC 380 2002
KTM EXC 380 2001
KTM EXC 380 2000
KTM EXC 380 1999
KTM EXC 380 1998
KTM GS 250 1994
KTM GS 250 1993
KTM GS 250 1992
KTM GS 250 1991
KTM GS 250 1990
KTM GS 300 1998
KTM GS 300 1997
KTM GS 300 1996
KTM GS 300 1995
KTM GS 300 1994
KTM GS 300 1993
KTM GS 300 1992
KTM GS 300 1991
KTM GS 300 1990
KTM MX 250 1994
KTM MX 250 1993
KTM MX 250 1992
KTM MX 250 1991
KTM MX 250 1990
KTM MX 300 1994
KTM MX 300 1993
KTM MX 300 1992
KTM MX 300 1991
KTM MX 300 1990
KTM MXC 250 2003
KTM MXC 250 2002
KTM MXC 300 2003
KTM MXC 300 2002
KTM SX 250 2002
KTM SX 250 2001
KTM SX 250 2000
KTM SX 250 1999
KTM SX 250 1998
KTM SX 250 1997
KTM SX 250 1996
KTM SX 250 1995
KTM SX 250 1994
KTM SX 250 1993
KTM SX 250 1992
KTM SX 250 1991
KTM SX 250 1990
KTM SX 300 2003
KTM SX 300 2002
KTM SX 300 2001
KTM SX 300 2000
KTM SX 300 1999
KTM SX 300 1998
KTM SX 300 1997
KTM SX 300 1996
KTM SX 300 1995
KTM SX 300 1994
KTM SX 300 1993
KTM SX 300 1992
KTM SX 300 1991
KTM SX 300 1990
KTM SX 360 1997
KTM SX 360 1996
KTM SX 360 1995
KTM SX 380 2003
KTM SX 380 2002
KTM SX 380 2001
KTM SX 380 2000
KTM SX 380 1999
KTM SX 380 1998