Evinrude 65hp won't go to full throttle

[dan d]

My 1971 Evinrude 65hp 3 cyl won't run past 1/2 speed. Then it surges and occasionally I get full power. I cleaned out the tank,changed gas and ensured the filter is clean. Where should I go next? Thanks
Dan

 

[F_R]

Re: Evinrude 65hp won't go to full throttle

Read the thread Johnson 70 HP Lack of power by vision2000. Saves doing it all over again.

 

[vision2000]

Re: Evinrude 65hp won't go to full throttle

I think it may be like my problem. Be 100 % sure that all fuel pipes and filters are really clean. Every connection counts. Check that there's no dirt in the fuel pump. it could also be an air leak in the fuel outlet pipe inside the tank. Try using another fuel tank. See also that the fuel tank connection to the motor is not clogged. Try to bypass the connection and make a direct connection from the tank to the fuel pump. You have to eliminate one thing at a time. Lastly check the carbs.

 

[dan d]

Re: Evinrude 65hp won't go to full throttle

Read the thread Johnson 70 HP Lack of power by vision2000. Saves doing it all over again.

 

[dan d]

Re: Evinrude 65hp won't go to full throttle

Thanks F R and Vision 2000! I'll look there first. My problem started with year old gas and the red bacteria in my tanks. I cleaned the tanks out and put in new gas/oil, cleaned the fuel filter also. I did try switching tanks to no avail to known good tank. I will try cleaning the fuel pump and the connection next. Thanks much.

 

[jall65]

Re: Evinrude 65hp won't go to full throttle

sounds like you got some crud in the carbs .
.

 

[dan d]

Re: Evinrude 65hp won't go to full throttle

When I cleaned the tanks the pickup filters were clogged and there was little bits of decayed red silicone that the previous owner used instead of the proper gaskets when he opened up the tanks. I cleaned all that stuff out, blew out the pickup ends and replaced the OMC gaskets. Then I went to the filter and only found one small granule of the silicone in there. Could the fuel pump go bad due to the intakes being plugged? I also just checked compression and all three are at 140 psi. Thanks.

 

[F_R]

Re: Evinrude 65hp won't go to full throttle

All the crud you describe sure would lead to gummed up carburetors. Remove the hex head plugs from the bottom of each carb (air silencer removal req'd) and see if the inner end is clean or is it coated with anything? Unless it is shiny clean, you might as well keep going and remove and clean the carbs. Pay particular attention to the orfice plug which is deep in the hole the hex plugs came out of. A special screwdriver is required to remove them. Soaking them in a dip-type carb cleaner will clean them without removal if you soak it long enough. Stale crappy gas will destroy a fuel pump. Best way to fix a fuel pump is to put a new one on.