For a new BX I got about 30 hours before troubles really were frequent. At 30 hours and less than a year ownership got the dealer to change the fuel sensor, since it was goofy. They put in a new one. Troubles were mainly like the poster had and they continued. Perhaps the rust from the old floats were still in the tank. Even after yanking the tank at 210 hours and cleaning it (didn't notice any crap coming out however) had frequent stalling, apparently due to fuel filter plugs. I blamed it thereafter on some jelling of the STABL Biocide which I figured might stop growth of "bugs". That stuff won't flow at 30 degrees F. Disposing of all fuel and installing an outboard first stage fuel filter (much larger), it seems to be OK, but time will tell. By the way, don't fall for buying cheap fuel pumps (from Hong Kong). I got 10 hours on them before they quit. For a person thinking of a BX, I say think twice. Look for gravity fuel feed, no fuel pump.