Hi all, wondering if any of you have experienced similar, have an otk 401rr with a new Rotax 125. I can run the kart forever on the stand but when driving I can only do about a lap before the carby physically runs out of fuel, I changed filter, replaced fuel pump and fitted spare new carby but still occurs.
has anybody seen any vacuum issues?
That’s not a lot of information to go on, but what evidence do have that “when driving I can only do about a lap before the carby physically runs out of fuel”? (that’s an unlikely scenario in almost of situations short of having a pinched fuel line somewhere)
What are the symptoms that the kart/engine exhibit when it starts to shut down?
What color is your spark plug? (for instance is it black, nearly white, brown)
How does the engine respond when giving full throttle from a slow pace to top speed?
A pinched fuel does sound like a likely candidate. Also, there is a possibility that the breather for the tank is getting pinched off as you drive. You said you switch carbs, but is the tube that runs over the top the carbs cut open at the top? Could the floats on both carbs be set way too low?
Good luck and let us know your progress.