Hi i was wondering how much transmisson oil a 2003 sx125 holds thanks.

I doubt if the engine is seized but with the loss of oil in the transmission it could be a seized bush/ bearing in the torque converter or input to the ransmission

To much trans oil or wrong oil

Could be your tranny filter change that and see if it helps

Your drive belt is wore out. Replace it!

you got a blown head gasket or warped head

Thank you for contacting FixYa with your inquiry
Capacity - Transmission Oil Gear Oil (All 125/150 Models) 0.70 Liters (0.74 qt) Engin Oil 15W/50)
Guideline Use High quality 2-stroke engine oil of a well-known brand. KTM recommends Motorex products Su[plier Motorex - Cross Power 2T
This service manual information link might be helpful: should be same for all years. http://www.ktm.com/uploads/tx_ktmproduct/techdocs/6101L0_34254324.pdf.

If the carbs are the same inlet and outlet size and you swap the jets, it should work fine

The oil tank is on the bottom of the transmission. If you look under the bike, the oil drain is drain plug closest to the left front of the tank. The drain closest to the center drains the transmission. Check the oil in both the engine and transmisson before starting the engine.

Good Luck
Steve

I recommend that the fluid be changed and the screen cleaned every 40,000 miles. Good Luck! I hope you find this to be very helpful!

try checking the fluid level if it is even aa half pint off it can cause shift problems, if it is low add some Lucas transmisson oil condtioner this will help it shift smoother. also look at the color of the fluid is it brownish in color? if yes then it's time to change the filter and fluid. if you take it to a shop they chagre about $150.00 but it will keep you from damaging the transmisson. the oil and filter for the transmisson should be changed every 30,000 miles on any car. Thisis oone of the most overlooked items of maintence on cars peopel simply don't know about change the filter and oil till they have to pay for a new transmisson.