1978 55hp evinrude idle problem

[Todd 1669]

I have the above motor and this issue. When starting cold I have to keep giving it gas untill warmed up. No big deal. When putting it into gear unless I have my hand on the throttle constantly giving it fuel it will stall out. If warm and I let it sit and idle it will eventually (2-3 minutes) just run itself out and stall. It will start again but when puting it into gear it will stall out. At WOT or any running speed it runs great. You just have to take 10 minutes to get it running again if you stop.

 

[tashasdaddy]

Re: 1978 55hp evinrude idle problem

idle speed stop screw set too low, also, possibly dirty low speed jets. idle speed has to be set and fine tuned in the water, and in gear.

 

[Todd 1669]

Re: 1978 55hp evinrude idle problem

Ive set the idle all the way up on the throttle arm and was still having the same problems. I guess the way to describe the symptom is when giving it throttle from idle it sounds like its just sucking air.. If you VERY gently give it the throttle it will cough itself through and run fine at higher rpm..
I will check the low speed jets today.

 

[Todd 1669]

Re: 1978 55hp evinrude idle problem

A little update.. I pulled the carbs and removed the low idle orfice (sp) and think there was a little blockage in one. The were actually pretty hard to get out. I was worried about stripping them and having a real problem. I also set the plug gap at .037 from .030 and adjusted the idle linkage. Running it off of the ears it definetly idled better at lower RPM. We will see when it gets in the water how it runs under load.

 

[tashasdaddy]

Re: 1978 55hp evinrude idle problem

you have to set the final idle speed in the water for final adjustment, due to back pressure on the exhaust.

 

[Todd 1669]

Re: 1978 55hp evinrude idle problem

you have to set the final idle speed in the water for final adjustment, due to back pressure on the exhaust.

Went out on the water today to test it. Ran terrible at idle. I turned the screw almost all the way in and it still wouldnt hold an idle very well. Still wants to cut out when giving it throttle from idle. Almost put me into the rocks when it stalled out and kept stalling out when I would put it in foreward gear.