Yes, it is possible to flood a diesel generator. This can happen if too much fuel enters the engine and prevents it from starting properly. This can be caused by a variety of factors such as a malfunctioning fuel injector, a clogged air filter or a faulty fuel pump. If your diesel generator has been flooded, you should turn off the fuel supply and allow the excess fuel to evaporate before attempting to start the engine again. It's also important to check the condition of the fuel system and address any issues that could cause flooding in the future.