1978 evinrude 9.9 fuel problem

[awulber]

i have a 1978 evinrude 9.9 it idles fine and will run good for a few minutes, i rebuilt the fuel pump and it still dies when at higher rpms , if i pump the fuel primer bulb it will keep running any one have any ideas thank you

 

[AlTn]

Re: 1978 evinrude 9.9 fuel problem

rebuild didn't work, or you have air leaks in the fuel system

 

[tx1961whaler]

Re: 1978 evinrude 9.9 fuel problem

Usually if it keeps running while pumping the bulb it means there is a problem with the fuel pump or the tank is not venting properly or there is a problem with the primer bulb check valves.
Have you checked to see if it is actually pumping fuel? Pull the fuel line from the pump to the carb while it is running to see if fuel comes out. Be careful and don't set yourself on fire or anything...

 

[awulber]

Re: 1978 evinrude 9.9 fuel problem

if my fuel lines were letting air in wouldnt they leak fuel out also, i looked at them and didnt see any cracking where else would air be getting in at
and i just messed around with it it will run for 15 minutes just above an idle now but when you rev it up it starts to die thanks for the help

 

[OptsyEagle]

Re: 1978 evinrude 9.9 fuel problem

Here is what you do.

1st check is to open your gas tank cap and run it again. If you need to keep squeezing the primer bulb, then tank venting is not your problem. 2nd test, if you have another fuel line for the tank, try that, if not leave it to the last test. Next, pull the fuel line from the fuel pump to the carb. Remove spark plug boots so as not to start the motor. Pull on starter rope and see if fuel pumps out of pump. If it does, then your fuel pump is probably fine and it is most likely your check valves in the primer bulb of the line to your tank. They do fail.

If your pump is working, your tank is venting and your primer bulb is working, then it must be an air leak somewhere. Your fuel is not flowing to your carb automatically, since you have to manually push it. Those are really the main areas that allow fuel to flow properly.