77 evinrude 140 not running right.

[Bdt 1967]

I have a 1977 Evinrude 140 horse outboard. The engine starts right up and runs strong, but it will not idle right. I can start it up and as soon as i put it in gear it tries to die. (especially reverse) once in gear it will idle all day long around 800 rpm. But when I put it in neutral it sounds like it loads up and eventually will die. I had the carbs rebuilt last season. I checked the plugs and they appeared to be ok but that is no guarantee. I dont know if the low idle adjustment is wrong or what. Also if i am in forward gear and take it into neutral let it idle for a second or two then reverse it generally will die. It is worse when the boat is cold. Any ideas are greatly appreciated.

 

[tashasdaddy]

Re: 77 evinrude 140 not running right.

what have you checked? are you running old gas? did you winterize it? do you use seafoam in your fuel. check spark on all cylinders, it really sounds like you are running old gas, or have a varnished, dirty low speed jets.

 

[Bdt 1967]

Re: 77 evinrude 140 not running right.

I did winterize it last season, and i have run 2 full tanks through it this season. In the tank I am running right now i am running sea foam, I am running a 50:1 mix. This tank seems better than any of the other tanks I have run in the past, it will go into forward almost every time without dying out. Reverse still sucks. I will check the spark next but with how strong it runs from 1.5k to 5k rpm I cant imagine it being spark, the boat runs 50mhp no problem.

 

[tashasdaddy]

Re: 77 evinrude 140 not running right.

try setting your idle speed stop screw up just a little. but one carb, could be having a problem, and not operating properly at low speed. to check, pull the plug wires individually. listen for the rpm change. if it does not change there is a problem with that cylinder, which could mean it is not getting fuel, thus no lubrication.

 

[Bdt 1967]

Re: 77 evinrude 140 not running right.

I will check that this week, and let you know what I find.

 

[Bdt 1967]

Re: 77 evinrude 140 not running right.

I forgot to say, when trolling or driving in no wake zones, it will run smooth for about 3-4 seconds then cough, then smooth out for 3-4 seconds then cough again. It doesn't seem smooth at all in the lower rpm range.

 

[LubeDude]

Re: 77 evinrude 140 not running right.

3-4 seconds then cough, then smooth out for 3-4 seconds then cough again.

This is a clear indication of a problem, It could be reeds and it could be air in the fuel. Check for cracked fuel lines. You might just replace all of the fuel lines, I bet they are hard as a rock!

 

[Bdt 1967]

Re: 77 evinrude 140 not running right.

That makes sense i will check the fuel line first, how hard is it to get to the reeds, on my old boat they were located just under the carbs, is that the case on these engines?

 

[tashasdaddy]

Re: 77 evinrude 140 not running right.

i'm voting a carb problem in atleast one of them. reeds are possible but a far stretch. sounds more fuel mix.

 

[Bdt 1967]

Re: 77 evinrude 140 not running right.

I had the carbs rebuilt last season, where do i need to start on troubleshooting the problem. Do you know if there is a low idle mixture on these engines, i don't have a manual for this engine yet, but would like to get it fixed soon.