Re: no spark on num 1 cyl
I'm assuming you have a built in tank. If there's a way you can actually look into the tank through the opening where the fuel sending unit is mounted, that may be helpful. See if there is a leaf or some type of similar debris that may be intermittently blocking the fuel pick up tube. Also, make sure the gas tank fuel vent is not plugged. As the gas gets used up, a blocked vent will create a vacuum in the tank that the fuel pump can't overcome.
Check the fuel pick up tube. Depending on the design, typically the fuel pick up is a metal tube that goes all the way down to within an inch or so of the bottom of the tank. The fuel pick up should be located towards the stern of the boat on the gas tank. I've seen a few where the fuel pick up tube is pretty short and a length of rubber hose is used to extend it down. The rubber hose gets rotted and falls off, or has big cracks in it so the fuel pump only works when the tank is full and as the fuel gets lower, fuel delivery get spotty depending on how the boat is tilted.