Jcris - Do you by chance mean you are having a hard time starting the boat cold after it sat for a few days between uses? If so I might call that normal as the fuel is likely evaporating out of the float bowl in the carb. So when you go to start it, you pump it once or twice but there is no fuel in the bowl to get squirted into the venturies when you pump the throttle. So you need to crank it a few seconds to refill the float bowl, then pump it a couple times, then start.
I had a Volvo 4.3 GS with electric fuel pump and 4 barrel. That was the same way. If I used it every day like on vacation, pump it once, touch the key and she's off and running.
On the other hand, if the boat sat for 3+ days and especially if it was really warm out I would have to crank it for a few seconds to refill the float bowl, then pump it once or twice and I was off.
I was going to do the exact thing you want to do with an electric switch but never did, , I traded this spring. If you do wire in a switch you want to use a momentary push button switch so as soon as you take your finger off the switch the pump stops. It doesn't have to be a push button, but it NEEDS TO BE a momentary switch. As apposed to a "maintained" switch which will stay on until you shut it off.
I was going to wire it such that when I pushed the button that would power the fuel pump relay which would turn on the pump. But like I say, I never did it.
My new to me boat is carburated. Same story except that now I have a mechanical fuel pump so I couldn't wire in a switch if wanted to.