Priming the carb

Turn the key on, the pump will run approximately 3 seconds, crank the engine, the pump will run while cranking and for 1-2 seconds after release of the key back to run. If you cycle the key a few times, you will get the same result. On, count to 5, off, turn back on, count to 5, repeat. Depending on the length of the rig and the routing of the fuel lines, it could be one or two cycles to several.

Follow straight down from the Starter Relay (fender mounted solenoid) through the Diode to the Tank Select Switch. The not-so-good idea was that the Fuel Pump gets powered up when the starter is engaged. That's not very good because you want the carb primed BEFORE you crank it. Besides, the cranking sucks the voltage down so the pump isn't as effective as it should be.
A pushbutton switch is the hot setup.
I used to lift the hood, pull the Blue wire off the Starter Relay and hold it to the Positive Battery Terminal to run the pump. Switch is much better, particularly in say the Dark, the Rain.

Clicky I think this is mine.

I have the parts manual and the shop manual. I will check the schematics and see if it already has a priming circuit.

There is a fuel pump relay in many rigs that primes the carb or injectors. Look in the fuse blocks for such a relay.

Perfect idea, I did it about eight years ago. I let the fuel pump run for about five seconds, continue to hold the bypass switch, pump the throttle six or seven times and then turn the key. Release the switch after it starts.

Mine now starts almost instantly every time, great improvement. You can also listen to see how the pump is running if you are having trouble.