Boat running/ not running

[Salmon cannon]

I've been having this problem recently. Most of the time when I got out on the big lake. I can get out just fine engine runs great. Coming back after a 4-5 salmon troll at 600-800 rpm. Coming back at 2500-3000 rpm. I will just be able to get it up on plan. Then she sputters and starts to miss and will die if I'm not fast enough to throttle her down. I've put new points, condenser, plugs, plug wires, carb has been rebuilt. I don't know what it could be. Maybe fuel related. Haven't checked. But looking for opinions. Thanks in advance.

[1mainiac]

I had a similar problem for several years spent hundreds of dollars and had several Muskegon shops attempt to fix it. In the end the problem was the ballast resistor had been removed and voltage was too high at the coil. High coil voltage causes the coil to get hot and break down. Runs great when cold trolls fine but will not run in when hot often sputtered and acted like it was out of gas. Most coils will say right on the side if they need a resistor or not but a simple way to tell is check the voltage going to the points when running. At idle you should see between 6 and 10 volts to the points As it warms up at idle the voltage will drop slightly when you rev it up the voltage will increase slightly.