i have used these fuelers for yrs. but they do have problems.most of the time they evently get a leak.have one in a plane took 2 yrs. to realize the valve got a leak and started to suck air only happen at full throtle so it was hard to find.best fueling system so far i've used is the fuel dot its just a "t" fitting in the fuel line to the tank and capped off with a stoper after you fuel unless the line gets a hole in it or you forget to put the stoper back in its fool proof(or should i say fuel proof).
roy