It is a float needle problem, end of story, sometimes they will destroy your mind, they are the most annoying carby ever made. All I can ever do is keep swapping viton tipped needles and primer caps and eventually I get a combination that works, that doesn't leak from the needle/seat and a needle that does not stick in the seat. There is no rhyme nor reason to any of it, I get so angry with these when the needle/seat won't work and trust me the failure rate on these is about 50%