I think the sender is right. It had one bar, and I put 7 gallons in it, and it went up to 5 bars. I used it for 2 hours, and it dropped down to 3 bars over that time. My thoughts were the suction hose, but I didn't know if this was a common problem like in older ford diesel trucks... the suction hose breaks off and doesn't suck anything below 1/4 tank. Anyway, if the fuel in the bobcat runs low, your can use the primer bulb to suck up more fuel, and it will run for a few minutes, then sputter and shut off. I was also contemplating a fuel pump problem too. But, if the suction hose is made of hard plastic, it could have cracked or split, which would make sense too. The machine has 4400 hours on it, so it could be anything, and I don't have the service records from the previous owner (I bought it with 4000 hours). Any thoughts?