Had one of my guys running the flail today cutting right-of-ways. He calls me on the cell and says the mower is losing power and shutting off every so often. Checks common stuff like air filter etc...all seem fine. Calls me back in a few minutes and says he has noticed that when the machine loses power or shuts off the fuel gauge indicates 1/4 tank of fuel or less. When the power comes back up the gauge is back up to reading full where it should be. Anyone have any ideas about this? I am very unfamiliar with diesel engines. First trouble this machine has given us. BTW it has around 600 hrs. on it and routine maintenance provided on schedule.