ATHENA Cylinder Base Gasket for KTM EGS, EXC, LC4, SX, SXC 350, 400, 500, 540, 620, 625, 640 1989-2007

ATHENA offers this cylinder base gasket for KTM EGS, EXC, LC4, SX, SXC 350, 400, 500, 540, 620, 625, 640 1989-2007. 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 400?

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 50 h of hard use and every 100 h of leisure riding.

Specifications and fitting tips

• Thickness : 0.75 mm
• Manufacturer part number: S410270006041

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 · CENTAURO
• Piston : WOSSNER 8524D · WOSSNER 8821D
• Piston rings : PROX · 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:
KTM EGS 400 1998
KTM EGS 400 1997
KTM EGS 400 1996
KTM EGS 620 1998
KTM EGS 620 1997
KTM EGS 620 1996
KTM EGS 620 1995
KTM EGS 620 1994
KTM EXC 350 1994
KTM EXC 350 1993
KTM EXC 350 1992
KTM EXC 350 1991
KTM EXC 350 1990
KTM EXC 350 1989
KTM EXC 400 2006
KTM EXC 400 2005
KTM EXC 400 2004
KTM EXC 400 2003
KTM EXC 400 2002
KTM EXC 400 2001
KTM EXC 400 2000
KTM EXC 400 1999
KTM EXC 400 1998
KTM EXC 400 1997
KTM EXC 400 1996
KTM EXC 400 1995
KTM EXC 400 1994
KTM EXC 400 1993
KTM EXC 400 1992
KTM EXC 400 1991
KTM EXC 400 1990
KTM EXC 400 1989
KTM EXC 500 1994
KTM EXC 500 1993
KTM EXC 500 1992
KTM EXC 500 1991
KTM EXC 500 1990
KTM EXC 500 1989
KTM EXC 620 1998
KTM EXC 620 1997
KTM EXC 620 1996
KTM LC4 400 2006
KTM LC4 400 2005
KTM LC4 400 2004
KTM LC4 400 2003
KTM LC4 400 2002
KTM LC4 400 2001
KTM LC4 400 2000
KTM LC4 400 1999
KTM LC4 620 2006
KTM LC4 620 2005
KTM LC4 620 2004
KTM LC4 620 2003
KTM LC4 620 2002
KTM LC4 620 2001
KTM LC4 620 2000
KTM LC4 620 1999
KTM LC4 620 1998
KTM LC4 620 1997
KTM LC4 640 2006
KTM LC4 640 2005
KTM LC4 640 2004
KTM LC4 640 2003
KTM LC4 640 2002
KTM LC4 640 2001
KTM LC4 640 2000
KTM LC4 640 1999
KTM SX 400 1998
KTM SX 540 1998
KTM SX 620 1998
KTM SXC 625 2007
KTM SXC 625 2006
KTM SXC 625 2005
KTM SXC 625 2004
KTM SXC 625 2003