hello all, My 60 hp merc Bigfoot will only start with the throttle all the way up and will stay running at 3/4 throttle. When i drop it to idle position the engine kills. I just rebuilt and cleaned all 3 carbs and rebuilt my fuel pump today and the problem still exists. all 3 cylinders have perfect compression and new spark plugs. i also replaced the fuel filter. this one really has me stumped.... any suggestions?

are u getting spark on all of them