Thanks for contacting FixYa with your KTM inquiry.
50 kilometers is equivalent to 31 miles. The tank capacity is 2.9 Gallons indicating you are obtaining a very sub-marginal 10mpg approximately.
A couple things to check would be:
- Leaks/cracks in the fuel line.
- Access fuel is going somewhere - is it making OIL/Going out the pipe? Seals or Jets!
- Excessive smoke out the pipe.
- Pipe color coming out of the cylinder head (Cherry Red = over fueling)
- Spark plug color - should be a nice cocoa brown is jetting is correct.
More than likely you have either a stuck float or a jetting problem. Both are very easy to fix.
Tap the float bowl with a back side of a screw driver and see if it frees up. Test ride!
For jetting, you can raise the clip on the needle a couple of notches so the needle lowers and this should help conserve fuel in the middle RPM range.
The pilot jet and tower will gobble up fuel like crazy at low RPM's if they are to large a diameter. Refer to your manual and check the stock size for jetting and start with that. Elevation and temp has some effect on jetting as well. Just sounds like more than likely your needle and pilot jet are over fueling the engine.
Hope this gives you a few ideas. Let us know if we can be of further service,