Spring is here and I'm back. The problem is solved and the cause was ......(drum roll for dramatic effect) ....... primer bulb orientation. I found this issue in a Google search and discovered it was my problem. Here's what was happening. The fuel tank in my pontoon boat is located such that the fuel line goes up a foot or so before going back down about two feet to the engine. The bulb is in the section of line going down to the engine. My intuition was to leave the bulb so the side where fuel exited was pointed down toward the engine. That was what was contributing to the problem. It seems that the one-way valves on each side of the bulb are held closed by springs that are weak enough to be affected by gravity. So when the IN end is up, that valve cannot fully close. Thus, some of the pressure the bulb should be sending to the engine is escaping back to the fuel tank. I tilted the bulb so the IN end was down and it got nice and firm with just a few pumps.
As for the fuel enrichment valve, I tested it two ways and it seemed to pass both tests. With the engine warmed up and idling, I manually pressed the black button down and immediately heard the engine slow as it was running too rich. When it resumed a normal idle, I pressed the key in (electric choke) and the engine again slowed due to the excess fuel being dumped in by the fuel enrichment valve. ... Now that the bulb is priming the system correctly, I'll see if the hard start problem I had last summer returns this year.
It's almost warm enough to jump in the lake. :laugh: