ATHENA Cylinder Base Gasket for APRILIA MX 125, RX 125 and KTM SX 125 1984-2006

ATHENA offers this cylinder base gasket for APRILIA MX 125, RX 125 and KTM SX 125 1984-2006. 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 APRILIA RX 125?

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: S410010006010 (OE), S410010006020 (0.40 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 : see the selection
• Piston rings : PROX 02.6225 · PROX 02.6220
• Coolant : LIQUI MOLY 1 L · TWIN AIR

Compatibility

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

Fits:
APRILIA MX 125 2006
APRILIA MX 125 2005
APRILIA MX 125 2004
APRILIA RX 125 1999
APRILIA RX 125 1998
APRILIA RX 125 1997
APRILIA RX 125 1996
APRILIA RX 125 1995
KTM SX 125 1986
KTM SX 125 1985
KTM SX 125 1984