82' evinrude 75. Idle issues?

[Drogers91]

Rebuilt the power head fuel pump new fuel lines rebuilt carbs. Im having problems at ifle i can choke it get it to crank and it will idle for about 30 secs to a min befor it starts to bog and shut off. At this point if i tap the choke it will prime the carbs and idle back up and do the same thing. This only happens when i have the boat in the water and backpressure on the exhaust. With the muffs it runs fine . When i remove the airbox. It is very wet with fuel mixture. I have 2 ideas. An air leak in my fuel line Or my carb floats set to low? Has any one had this problem Or any idea where to start? I have a clear fuel filter in line right befor the motor and it stays full with fuel. The entire time? Help!!

 

[emdsapmgr]

Do a test. When the engine is running, constantly prime the fuel hose bulb. If the engine keeps running through all the rpm ranges as long as you keep priming the bulb, you may have a fuel restriction. (lean condition.) The fact that the engine picks up if you choke it already verifies that.... A lean condition may be a fuel restriction or even a weak fuel pump. What's happening is that the engine is consuming more fuel than the fuel system can supply. Any engine will run fine on the garden hose where there is no backpressure on the prop. It's when the prop exhaust is 20" underwater and shifted into forward gear-that you need the engine running correctly. A different set of variables when in the water. It's normal for the top carb to spit a little fuel mist when the engine is running. That's part of the rotating assembly oiling system.