Mechanical fuel level gauges may not always be accurate. Unlike a vehicle that is moving and using a higher percentage of its tank's capacity, a generator tank has no movement; causing the fuel to become stagnant. Mechanical gauges may also stick in a position until vibrations break them free.
Low level alarms must also be addressed, as they provide the same failure alarm. Some generators are equipped with "Low Level Shutdown" or "Critical Fuel Level Shutdown." These shutdowns are there to prevent the fuel system from drawing in air when running out of fuel is eminent. This shutdown alarm was not very popular in the Y2K days. If your generator was installed during this time, you may wish to retrofit it, as it most likely will not have this shutdown. Bleeding air out of a fuel tank can be an extremely difficult procedure.
Running out of fuel due to plugged fuel filters can be prevented by maintaining the fuel tanks, and periodically checking them for water and contaminants. Water or moisture in fuel can be damaging to diesel engines. It is also important to build relationships with fuel vendors that you can trust and rely on to deliver clean fuel. If you use fuel polishing as an alternative to cleaning your fuel, check with your vendor to see if their fuel is affected by the chemicals; fuel polishing may not be able to remove water.
Fuel filter plugging should be expected with the new ultra low sulfur fuel, which has a very high detergent level and will clean out your lines and whatever else it is in contact with.
Engines equipped with electric shut off solenoids should always have a manual bypass. There are several reasons to have shut off solenoids; large remote above ground tanks can gravity feed to the engine, over pressuring the seals in the pumps or injectors, and causing the fuel to mix with the oil. Solenoids should be DC power activating at the time of initial crank signal, and remain open until after the engine makes a complete stop.