Starts but dies

[THG]

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?

[deadeye]

When you say you put in "7 gals to fill the tank", I'm assuming the tank was over half full of old gas.  You will probably need to drain the tank and use only new gas.  Also, there is a good possibility that water got in the tank after being stored outdoors for years.  My guess is the main jet is clogged and the idle jet is the only one suppling gas to the engine.  Or, possibly the fuel line (or squeeze bulb)  is not allowing a full flow of gas.  Could be a clog or break allowing air to be sucked in at high speed.

[Swany]

I would agree with Deadeye, if you put 7 new gallons on top of any old gas you are not helping your cause. If it was an empty tank I would check the carbs.

If it has been sitting outside since '07 the carbs need to be cleaned. Your main could be clogged, your floats or float needle could be stuck...Is there an inline fuel filter? That could be stuffed up and not allowing for good flow past idle.

[Fishabass]

Carb Needs to be cleaned. That discription is usually the Jets in the carb that are gummed up.