Equipment that is used intermittently or rarely can always present unpleasant surprises. Stale or contaminated fuel can make them hard or impossible to start. Low oil level: modern motors have motor protection sensors that detect low oil level and won’t allow the motor to start. Mud wasps can make a nest in the muffler (happened to me) and/or air cleaner and totally stuff a pump, and you won’t even see it.
So you need to test.
Not just the pumps, but any taps, valves, hoses and nozzles, end-to-end. I have had nozzles rust out and gate-valves fail.
