Jeff I had one yesterday, one of the early viton tipped ones so probably near 18 months and just for some reason it decided it wouldn't play ball. What I tell people who can understand what I am saying is if it doesn't start, give the top of the carby a tap with a screwdriver handle and this usually makes the needle drop. Not sealing is a problem that seems to fluctuate, I get several in a row that play up then it seems to go away. Problem with the sticking is you can't see that it isn't working and the clear plastic tube is not too fuel friendly
