fuel pump

[jeff butzlaff]

I just rebuilt the fuel pump on a 1969, 55hp Chrysler outboard. The engine initially performed good after the rebuild, although it seemed to smoke more than usual. After a few starts the engine seems to be getting to much fuel then only operated at idle to slow speed. I have excessive amounts of fuel coming from the exhaust when idling and spark plugs are wet. Will I need to adjust the carburetor or is there a way to reduce the fuel pressure?

The boat ran good prior to the fuel pump problem, the only indicator I had fuel pressure problem was loss of power at full throttle. The Diaphragm had a pin hole in it and was replaced. I would think that I wouldn't have do do anything with the carburetor if the engine was operating properly prior to repairing the fuel pump. What is my next step?

 

[eurolarva]

Re: fuel pump

Welcome to Iboats. When you did the fuel pump did you only replace the diaphram and gasket? Turn the screw on the idle mixture screw clockwise till it lightly seats while counting the turns then set it back. How many turns down to 1/8 turn accuracy. It is located above the choke recessed into the upper part of the carb with a slotted screw. Pull both plugs. Do they look like they have a similar type of burn? What type of spark plugs are they?

 

[jeff butzlaff]

Re: fuel pump

The Diaphram was bad, one of the valves was in pieces in fuel pump body. I tried to get new valves at local dealer, he told me they no longer were available through manufacturer . He had an engine with fuel pump body with valves, so I gave it a try. I assume they were good, better than what I had.

I am not sure what you mean by 1/8 turn accuracy. Plugs are champion L82C and are black in color, they were wet and look simular. I will try what you suggested once I am sure what you mean. If it takes 5 turns to seat, you ant it turned back counter clockwise 5 turns + or - 1/8 turn?

Shop Manual lists to much fuel pressure as a problem, doesn't mention that fuel pressure can ge adjusted. Can it be adjusted

Do you have suggestion for testing out of water, as I have to trailer to a lake each tim I do soemething and I don't like having the fuel going into the lake like it has.

 

[mthieme]

Re: fuel pump

For what it's worth...
I went through the same thing earlier this season with a Merc 35. Diaphram was shot and had the appropriate symptoms. After I fixed it, I had the same thing happen as you describe. Turned out to be a saturated float in the carb.
I replaced that and have been running her all season trouble free.

And welcome aboard.