Is it the fuel pump?

[topkicke8]

I have a 1976,55hp Johnson outboard. After i pump the fuel bulb and hit the starter my motor kicks right over. However after about 2 to 3 mins. the motor starts to die. If i pump the fuel bulb it will pick back up, and after a couple of mins it dies again. Does this sound like a fuel pump problem? Also would this pump take a Sierra 18-7820 rebuild kit. Thanks for any help.

 

[ondarvr]

Re: Is it the fuel pump?

Possibly, it can also be from an air leak in the fuel line, so check for leaks first. There are O-rings in the connectors on the fuel line, they may need to be replaced.

 

[topkicke8]

Re: Is it the fuel pump?

I replaced fuel line between the tank and the connector on the motor and checked the vent hose. Did I miss anything you can think of ? Thanks Bill

 

[ezeke]

Re: Is it the fuel pump?

18-7820 is the listed aftermarket kit; OE is 393103.

 

[Upstatehunter]

Re: Is it the fuel pump?

I was having the same problem. Turns out it was the float, needle valve and seat. Sounds like you may have something in the carb.

 

[topkicke8]

Re: Is it the fuel pump?

I purchased the rebuild kit 18-7820,and all of the gaskets fit, however the diaphragm is different. The one in the kit is just a rubber shaped gasket looking thing and the one in my pump has a area that flexes and has a round plastic dish like disc that the spring fits up against. I did find a number on the side of the pump 385781, but I can't find a rebuild kit for that number. Can anyone help me? Motor is a 76 Johnson 55Hp 55EL76E.

 

[ezeke]

Re: Is it the fuel pump?

The little plastic piece that the spring sits on is not part of the membrane, it just rests on the membrane. If the aftermarket kit does not have one use the old one, or you could try to find a new one, it's part # 304094: http://www.marineengine.com/newparts/part_search.php?part_num=304094&x=23&y=10

 

[jsb5717]

Re: Is it the fuel pump?

Could be several things: Sticky needle valve, bad fuel pump, dirty fuel filter, poor fuel connection...

My 79 15 horse was doing the very same thing. I assumed fuel pump. But I took it apart and found it intact. I cleaned it well. I removed the little metal mesh screen filter and cleaned it very well. I put it all back together and it works fine.

 

[F_R]

Re: Is it the fuel pump?

There should be a new diaphragm support in the kit. Don't let the stem thing on one side of it fool you. Snip that off. It is called the "gate" by injection molding people. They trim it off for you---unless the customer (Sierra) is too cheap to pay them to do it.