> The generator failed to start as a result of contaminated fuel despite monthly tests.

I don’t think this is he first time I’ve heard such a thing. I wonder if the people running such tests know how long you have to run the generator to flush the fuel lines? And aren’t there failure modes for ICEs - and diesel in particular - where the engine stops working once it reaches operating temperatures?

I had a car that would occasionally conk out due to a damaged O2 sensor (due in turn to a crack in the manifold).