Hi Gray, Firstly I would check would be the vent hole in the fuel cap itself to see that it is clear, and secondly that the fuel filter in the tank (which is fitted to the fuel tap itself) is clean. If all is well, disconnect the fuel line to the carby turn the fuel tap on to different settings and observe what is occurring.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl