Its the needle and seat ,will have dirt in it .Are you running a filter .You will have to take out the needle and seat ,then tap in your hand and blow clean ,refit and reset float levels .You need to take out side plug to get level right ,just so a small amount of fuel comes out when you give the car a side shake ,have a rag to catch fuel overflow .Start with needle screwed down , unscrew plug check level ,if low put side plug back in and do again and again to right . Good luck,would help if someone could do this for you . cheers glenn .