Engine runs fine up to 3/4 throttle at 4000 rpm. If you go past that it stars to bog down. When I remove the spark arrestor I can get it to run about 4500 rpm before it starts to bog done. All 3 carbs have been rebuilt. Fuel pump rebuilt. All new fuel line and spark plugs. Boat shop believes it can’t suck in the air it needs, yet compression looks good. Any suggestions?