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Boat motor losing fuel HELP!!!!!!!!!!!!!!!

H

Hornet22

New member
'm at a loss. I have 2003 Mercury 50hp 2 stroke motor. My problem is when I idle or trolling at near idle speed i loose fuel pressure. If i pump the bulb i'm good to keep going. If i'm at WOT i'm good to go. I'm going to list everything i have done. Any help is appreciated!!!
Last fall i rebuilt the engine top to bottom all OEM parts. Runs great.
cleaned carbs (soaked, sprayed then air blow out)
just rebuilt them again last week (hoping this was the issue. NOT!!!!
replace line w/ bulb (1st one would collapse and not open till next day) replaced it again now losing pressure. I can pump it and leave it sitting it doesn't loose pressure.
I have replaced, pick up tube, check valve on tank, tried cracking the fuel cap, all fuel lines on motor, new quick connecter for fuel line both sets, replaced the T valve coming from the solenoid, i have rebuilt the fuel pump twice now, and anything simple you can think of i have checked or replaced.
Now sometimes when i pump the bulb as tight as it will go i can hear a slight squeal sound. not always but sometimes idk if thats what causing to loose the vacum and loose pressure. I have checked the floats to the book and they are within specs (not sure if i should adjust them anyways????
I'm out of ideas and ready to beat my head against the wall.

I have read about sycronizing the carbs? i think this is more a 4 stroke thing. not sure.

Also does the fuel solenoid (not sure exact name but it helps to crank boat when you push key in) be bad and causing the loss of vacuum? When i push key it clicks and if its warmed up and i push key it starts to bog down like its being flooded so it seems its working. But i read somewhere it could be working but losing vacum. Can you rebuild, or clean this item?

Please help!!!!!!!
 
If you push the rivets that holds the check valves io tight, they will buck up and not seal causing the pump not to operate correctly. It will work fine a WOT.
 
Now that is interesting. That is new to me. So how do i need to fix? Whats the proper procedure to put the check valves in? Whats to tight?
I do remember laying the valve down and using a screwdriver to press the rivet or dowel down into place. Could this cause my problem? How am i supposed to get the dowel pushed down?

Thanks for the info!!!!!!
 
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I also have another question. I have a set of 60 hp carbs for my motor. I tried to use them when i rebuilt the motor but i could never get it to run past 1/4 throttle. I tried to advance the timing but still no luck. I want to solve my current issue first with the fuel issue but also wanted to ask about the 60 hp carbs. I did soak and rebuilt them also the way you should. It would idle fine just bogs down past 1/4 throttle.
 
After the rivets are installed the rubber check disc and plastic washer must be perfectly flat. If not flip fuel body over and push out on the 3 rivet splits.
 
Ok i will try that once i get this fuel pump rebuilt again. I did tear down the fuel pump and in between the black diaphram (i guess thats what its called) the paper gasket had a tear right in the middle of it. How this happened is beyond me. Also i looked at the rivets you spoke about and the round disc being bucked up. Its hard to tell but since i'm going to replace anyways i'm not to worried about the current ones. I did watch a video that shows a black material and then the clear disc being put in what looked like a fuel pump like mine. When i got my boat and i had to rebuild the carb it never had those in it, just the clear disc. Do i need to put the black piece then the clear disc on it also? i never understood how that clear disc would seal up right?

Also any help on the 60hp carbs?
 
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