I have a 1993 17 foor tracker aluminum boat with a 60 hp evinrude 2 stroke 3 cylinder motor. When I start the motor, I push in the key and it start up and idles. I put it in gear and it will run for a minute or two and then tries to die. I can push the key in again and it will run for another minute or so and the die if I don't push the key in again. Also if I give it more throttle while in gear, it will die unless I feather the throttle until it reaches 2000 rpm and then it will plane out and run fine until I try to idle it in gear again. I can't load the boat using to motor because it will die again. I've taken it to boat mechanics and had the carbs cleaned and adjusted and had a different prop put on which helped a little bit. I also had the vro taken off and new spark plugs put in and also a new fuel filter. Any help would be appreciated. Thanks!