i have a 88 28hp johnson, in only runs on the bottom cylinder, i have cleaned the carb really good and have even replaced the small washer abouve the flot, it has really good spark on both coils and I even tried switching coils, it seems that the top cylinder is getting to much fuel for some reason, it will run on the one bottom cylinder but wont idle, when i take the gas hose off the motor it will start to race and runs good and at a high rpm till it starve for fuel and stalls, anyone have any ideas, new plugs also and have switched them also?????