I have a 1996 225 mercruiser outboard. Every time I take the boat out, it starts fine and idles fine, but when I get to 1200 rpms, and try to accelerate, the engine stalls, It restarts fine and will stall again. Sometimes if I go on in this manner, it sometime revs up and when I accelerate it will go and run like a top. It will run like this, until I put it back in neutral, then the process starts all over again. I just bought the boat. The fellow that owned the boat passed away and it set for a year and 1/2. I was told there was stableizer in it. We put in 80 gallons of fuel into a 110 gallon tank to fill it up. We put enough drygas in it for 60 gallons, we changed the fuel filter, put in a water separator, and even put in a new starter switch, because we thought maybe the choke was sticking. We also changed the primer bulb because it always seem soft. Nothing seems to work.