Fuel problem???

[kthurman]

I have 1990 40 hp evinrude. Only way I can get to start and continue running is with throttle pushed forward while in neutral.
I had it on the water and it sounded normal but would not go past 3000 rpms. sounds like a fuel problem to me but wanted somebody else's input. Have already checked spark and compression and they are fine. Thanks for any help.

 

[brian3127]

Re: Fuel problem???

Have you cleaned the carb

 

[kthurman]

Re: Fuel problem???

Boat has been in use. Ran great a couple weeks earlier. Gas was not old. Acts like not getting enough gas.

 

[brian3127]

Re: Fuel problem???

When it is running have you squeezed the primer bulb. Is there a difference. Check the fuel pump. There also a possibility that something broke loose in the fuel line or pump and made its way into the carb

 

[kthurman]

Re: Fuel problem???

Tried that did not help. Does not seem to flood when choking or throttle open when starting. How hard is it to clean carbs on this motor. I have worked on older ones.

 

[brian3127]

Re: Fuel problem???

I don't know, I have a 1975 Johnson 40 hp and its not hard to rebuild. Go buy a rebuild kit an a manual for you motor and it wil tell you how to do it. And maybe think about putting a fuel filter in the fuel line after the primer bulb.

The reason for the rebuild kit is to put new parts in it since you have it tore apart. Take all the parts off carb and soak the carb in mineral spirits over night then blow air in every hole. Then put the new parts back on it.

 

[kthurman]

Re: Fuel problem???

Forgot to mention that it only has rpm problem while in forward under load. In neutral it is fine.

 

[brian3127]

Re: Fuel problem???

I'm not familiar with your motor. My carb only has a slow speed adjustment screw yours might have one. You might have to adjust it. I suggest you get a manual for your motor and that will tell you how to rebuild and adjust yor carb.