0.7 liters engine oil using Motorex Top Speed 4T 15W50.
.7 L
you dont, drain the oil and start again
40:1
KTM recommends Motorex Top Speed 4T15W50 for the 125SX.
You can find that info , as well as a lot more, here: http://motocross.transworld.net/2003/07/09/2004-ktm-125-sx-200-sx-250-sx-and-525-sx/
I personally use 32:1 of amsoil and regular unleaded gas for my ktm 125 sx 2003.
To check the oil in a KTM 125SX 2-stroke, first ensure the bike is on a level surface and the engine is cool. Locate the oil tank, usually situated on the left side of the bike, and remove the cap. Use a dipstick or simply check the oil level visually; it should be within the indicated range on the tank. If the level is low, add the appropriate 2-stroke oil until it reaches the correct level.
the ratio is 50:1 on my ktm 125sx, for every gallon of gas you have, you need to use 2.56 oz of oil. i use Amsoil, its expensive, but its the best synthetic two stroke racing oil there is. the gas should be light pink if you mixed it correctly. hope this helps
KTM says to change the transmission oil the amount called for is 0.7 liters engine oil using Motorex Top Speed 4T 15W50.
Gas (Unleaded 91 octane Recommended) to Oil Mixture (using Motorex Cross Power 2T or similar product) at a 40:1 and the for the transmission, use Motorex Top Speed 4T 15W50 ( 0.7 liters or 0.739681 quart).
KTM recommends .5L of Motorex Top Speed 4T15W50 for its ktm 85. It is important to use the current type and weight of oil as well as the correct amount to keep the engine running properly.
Engine oil, KTM recommends Motorex ATF Super (Dexron II Gear Oil) Premix, KTM recommends Motorex 2T.