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1984 mercury 50 hp fuel problem

F

fishing addict

New member
new to the forum as well as this setup the boat is a 1965 Star craft Explorer and the motor is a 1984 mercury 50 hp. I am having a fuel delivery problem the motor will run at lower speeds but at higher speeds the primer bulb needs pumped to keep it going.

I had bought a new fuel tank due to the original one he had been stolen. also tried running it with the fuel tank cap off as i thought it might be a tank vent problem "possibly faulty tank" still didn't fix the problem.

gone through both carbs they were very clean.

has all new fuel lines including the line with the primer bulb.

I cant think of anything else that might be causing this problem any help would be greatly appreciated.
 
I figured that would be the next direction to go but didnt want to spend the money if it was something different also I ordered the diaphragm kit for it when i install it and try it out i will give an update.

can you use any fuel tank for this motor or does it have to be a certain type of vent or design?
 
I figured that would be the next direction to go but didnt want to spend the money if it was something different also I ordered the diaphragm kit for it when i install it and try it out i will give an update.

can you use any fuel tank for this motor or does it have to be a certain type of vent or design?
 
Update on the motor got in the parts for the fuel pump installed them and the motor will run on muffs for about 2 mins then dies I tried pumping the bulb to see if that would work and it helps a little too keep it firm but motor still dies. also I went through the carbs again while they were out and didn't find anything any help is much appreciated
 
So I adjusted the air/fuel mixture screw after this and the motor will stay running by it self for 2 minuets and then starts to run out of fuel prime the bulb till hard and it will run another 2 minuest It will continue to stay running as long as I do this.

Can I run a low 2.5-4 psi inline fuel pump right after the fuel tank? Will this harm the fuel pump gaskets/ orphases?
 
Uh-oh! Some of them are way too restrictive (fine filtration) and that can cause serious fuel starvation.

The vacuum pumps on OBs are not strong enough to pull gas through a tight restriction. See what micron size that filter is--should be at least 25 micron or higher.

Jeff
 
I bought a 40 micron filter swaped it out. it runs longer 5 mins then runs out of fuel, fuel filter goes empty and shortly after it dies. Any other help is much appreciated.
 
None! Use the stock filter located AFTER the pump. Don't let anything restrict flow to the motor, and keep the hose short and without any upward loops between the tank and motor. (Upward loops allow the fuel and vapors to separate.)

Jeff
 
The fuel lines weren't stock when I got the boat and motor nor was the fuel filter I ran the new fuel lines as they were before. There are no loops in the fuel lines but it they are sloped up to meet the 3 way splitter to the carbs. So I need to order a stock fuel filter? Or will this 40 micron that I bought work?
 
I went back out to try to figure something out and had seen that when I pump the bulb to prime the bulb get hard but the fuel filter drains what would cause this?
 
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