[Mdub]

I have a 1984 75 HP 4cly. Mercury outboard. The engine had sat for a few years before i got it. Since then I have rebuilt the carbs, drained and cleaned the fuel tank, replaced all of the gas lines outside of the engine, new primer bubble, fuel filter, and new plugs. When I went to start the engine, the battery was completely dead so I had to jump it off my truck. The engine would only start when I engaged the throttle about 3/4 of the way. But after running it to warm up for about 5 to 10 min., when I pull back the throttle to let it idle, it just stalls out. It seams like it is not getting gas at idle. This is my first time dealing with a outboard and I am stuck.
Any ideas?

[bhile]

The fuel pump should have been rebuilt too after sitting so long.

[Mdub]

I rebuilt the fuel pump as well and it is doing the same thing. Is there a way to adjust the idle besides the idle screws in the carbs. I saw a idle stop bolt on the throttle assembly. Will adjusting that help?

[Mdub]

Any one have any ideas??????

[jbrown270]

Check your RPMs as you lower the throttle to see if they are too low. Was the needle valve/float level set correctly when you rebuilt the carbs?

[Mdub]

It die out just below 600 rpm. The needles are set correctly I did not adjust the float though.

[jbrown270]

if the boat is in the water, it should idle around 700-800 in neutral and around 600 in gear. If it is running on the water hose, they will usually idle a little faster (1000-1100) because there is no back pressure on the exhaust. Does the priming bulb get stiff? try priming it and watch the carbs to see if gas is dripping out. You should be about to squeeze the bulb firmly without any more fuel moving through the line. Incorrect float levels will sometimes cause fuel to leak from the carbs and cause the motor to slowly die like you decribed at low rpms, almost like it is running out of gas. Are you running on the water hose?

[Mdub]

Thanks for the info JBrown. I am not running it on a hose, I am running it in a tub of water just above the water intake vents. I will take the carbs off this weekend and check those float levels before I adjust the idle bolt and throttle cable.