Sounds to me like you may very likely need the carbs cleaned. A year is a long time to store a boat without proper preparations. Unless you winterized the boat by draining the carbs and adding a fuel preservative, the carbs should be pretty gummed up. Carburated 4-strokes have complex carbs that cannot tolerate varnish or contamination. There are a few things you could try. For starters remove the drain screw from each carb to see if there is varnish on the end of the screw, this would indicate that the carbs need cleaning. If the drain screws look good then squeeze the primer bulb several times to flush the fuel system. At first the fuel may come out yellow then it should clear up and come out clear. Put the drain screws back in along with a new set of spark plugs. (use NGK plugs, you can get them at the auto parts store for $2-$3.) While you're at it check your oil and look over the engine for anything suspicious. Fire it up, if the problem continues the first lolgical thing to do would be cleaning the carbs. Do not put anything in your fuel, not Sta-Bil, Sea-Foam, and especially not carb or fuel system cleaner. To put such additives in old fuel will have negative effects. If you dump your tank and add some fresh gas you could use some Sea-Foam, that would be worth while. Honda carbs have small o-rings and other rubber parts that could suffer from cleansing type additives. Try these things and tell us what you find.
