So today i was out on the water for the first time. with my old ass boat, the engine keeps stalling when i let off gas. after a hour of being on water it was running fine except the fact that it keeps stalling when i let off the gas and go into neutral. Besides that was running fine. SOOOOOOO now after 1 hour of being on the water not running boat hard at all, it started to jerk and then it the rpms where going nuts, the flame arrestor was somewhat clean when i left, now its black on inside and out, the carb is now really dirty on the top flap. Its a Double barrel carb mercruiser alpha 1 gen1 200 hp v8. i shuddered back into dock and luckily died right next to boat ramp. I am guessing it is a carb problem? would you agree with that?