1971 18hp Evinrude won't run without pumping bulb...

[stevenn]

Have replaced fuel pump and just replaced the line bulb but no help. Engine will start, idle and run fairly good at WOT as long as you pump the bulb to keep it going. Dirty carb or ?? Thanks. Another question while I'm here, where does the water from the water pump come out on this engine ? Want to make sure impeller is working.

 

[divinginn]

Re: 1971 18hp Evinrude won't run without pumping bulb...

Either the fuel pump is not working right or there is a air leak in the fuel lines. Check all lines esp. the ones on the motor,check the fuel pickup up in the tank to make sure it is not clogged,check all fuel line fittings to make sure they are working properly and not leaking. If it has been setting up, it would not hurt to clean up the carbs and put a new impeller in.

 

[mccarty]

Re: 1971 18hp Evinrude won't run without pumping bulb...

I have just replaced my fuel pump and all my lines and my motor is doing the exact same thing. same motor. Keep me posted if you find out what is wrong. friend told me I need a new carborator, but I just sunk over $100 and didn't fix anything.

 

[F_R]

Re: 1971 18hp Evinrude won't run without pumping bulb...

I have just replaced my fuel pump and all my lines and my motor is doing the exact same thing. same motor. Keep me posted if you find out what is wrong. friend told me I need a new carborator, but I just sunk over $100 and didn't fix anything.

It is a very rare case indeed when a motor needs a new carburetor. If it runs when you pump the primer, the carburetor is doing it's job. It is the fuel pump that is not doing it's job, and you are helping it by pumping the bulb. But don't condemn the pump till you have ruled out air leaks in the lines. Even a tiny leak between the pump and the level of the gas in the tank will admit air under suction. Most common place is the little pins on the tank outlet where the hose plugs on (assuming you have an original tank).

 

[mccarty]

Re: 1971 18hp Evinrude won't run without pumping bulb...

It is a very rare case indeed when a motor needs a new carburetor. If it runs when you pump the primer, the carburetor is doing it's job. It is the fuel pump that is not doing it's job, and you are helping it by pumping the bulb. But don't condemn the pump till you have ruled out air leaks in the lines. Even a tiny leak between the pump and the level of the gas in the tank will admit air under suction. Most common place is the little pins on the tank outlet where the hose plugs on (assuming you have an original tank).

new tank 6 months old.
are you talking about the male connector on the gas tank when you say "pins"? The male connectors are new with the tank, but the females are old..... Could this be a problem?

 

[Daviet]

Re: 1971 18hp Evinrude won't run without pumping bulb...

There are sealing o-rings just inside the quick connectors. Sometimes these get nicked by hooking and unhooking. They are replacable.

 

[mccarty]

Re: 1971 18hp Evinrude won't run without pumping bulb...

There are sealing o-rings just inside the quick connectors. Sometimes these get nicked by hooking and unhooking. They are replacable.

but, wouldn't that just cause a fuel leak. I have not noticed any fuel leaking?

 

[Les Robb]

Re: 1971 18hp Evinrude won't run without pumping bulb...

Hard to believe, but you can suck air and still not leak fuel. I guess under pressur the o-ring is forced back and creates a better seal. Anyway a mechanic once told me if he had his druthers it would be straight hose from tank to ball to fuel pump inlet with no quick couplers.

Makes sense but inconvenient with portable tanks.

 

[mccarty]

Re: 1971 18hp Evinrude won't run without pumping bulb...

Hard to believe, but you can suck air and still not leak fuel. I guess under pressur the o-ring is forced back and creates a better seal. Anyway a mechanic once told me if he had his druthers it would be straight hose from tank to ball to fuel pump inlet with no quick couplers.

Makes sense but inconvenient with portable tanks.

thanks i'll try that. check back in a few days and I will let you know how it goes. Thanks again.

 

[jay_merrill]

Re: 1971 18hp Evinrude won't run without pumping bulb...

Check the vent on the tank too - make sure it is open all the way.



???

 

[mccarty]

Re: 1971 18hp Evinrude won't run without pumping bulb...

I couldn't find just the o-rings locally, so I replaced the connectors. I also put in a new bulb even though mine was only 6 months old.
Put the boat in Saturday Morning and it ran better than it has since I got it.
Thanks for all of your help.

 

[mccarty]

Re: 1971 18hp Evinrude won't run without pumping bulb...

Have replaced fuel pump and just replaced the line bulb but no help. Engine will start, idle and run fairly good at WOT as long as you pump the bulb to keep it going. Dirty carb or ?? Thanks. Another question while I'm here, where does the water from the water pump come out on this engine ? Want to make sure impeller is working.

any luck yet?

 

[jonesg]

Re: 1971 18hp Evinrude won't run without pumping bulb...

Yoiu are causing crossed threads here.