Starts but dies

[Tinkhamtown]

Starts but dies

Son just inherited a 1984 StarCraft boat 18’ with a 140 Merccruise that has been stored outside up Fishers on M since 2007. We charged battery, cleaned it Saturday, put 7 gallons of gas to fill gas tank and took it to Bald Eagle to try out. It started on 4th try and idled quiet and smooth but when we took it out into the bay and tried to go faster it died. It would start and idle but when we tried to go it died again over and over again. Ended up where it would start run at idle a little bit than die. My question is this because of bad gas or carburetor problem and where should we start in the fixing process?

[Surface Tension]

If you have steel fuel tanks I'd at least remove them and clean them out.

Check the drop tube and check valve for each tank as well. Then inspect the fuel lines.

Replace the in-line fuel filter if you have one. Replace the fuel filter at the inlet of carb.

You may or may not have a sediment bowl on the fuel pump or a filter. Drain the bowl and replace the filter.

Now would be a good time to test the fuel pressure at the pump.

I'll assume you have a carb. Your carb is much the same as the carb on a vehicle of that year.

If you have a immediate stall or hesitation when giving it throttle that is a good indication the accelerator pump inside the carb is bad. A carb clean and rebuild is in order. You can check to see if the accelerator pump is working by removing the flame arrestor from the carb. Look and listen for good fuel spray while have someone apply throttle. Each time the throttle is pushed a spray will happen. On a cold start you might even have to pump the throttle a few times in order to get it enough gas to start.

[Moose-Hunter]

Sounds like fuel issues for sure... Frank seems to have a handle on it.