This little tale may be useful to someone someday.
Last Sunday I took a trip down the coast. The 6.5Kw Phasor genset ran smoothly all day powering three air-conditioners and the refrigerator. Late afternoon we are back at the dock with lines on, engines off and genset/aircos still running. Without warning the generator shuts down.
No obvious clues: tanks full, exhaust elbow cool, oil level good, no nasty smells; maybe fuel starvation? The Facet 12 volt lift pump in the pic below was silent and should have been making clonking sounds. The black wire is positive and showed a healthy 12.6 volts. The pump frame provides the ground and showed no continuity with the battery negative. The pump is bolted to a painted bracket which in turn is bolted to the painted engine block. All the fastenings were tight and the pump had run for 150+ hours with this less than perfect arrangement, before it lost its ground and, of course, stopped pumping. The new green ground wire from pump to engine block was the solution.
For the eagle-eyed: The spacers behind the pump flange allow clearance under the pump for a pot to catch the drips if/when removing the internal strainer at the base of the pump. The little brass needle valve on top of the filter is for burping out the air after a filter change.
If all else fails, read the instructions
If it ain't broke, don't fix it