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1980 Evinrude 140 Idle issues. HELP!!!

I really doubt you have a carb problem but I've been wrong before.........once I thought I'd made a mistake, but I was wrong. Ha!......not really!
Good luck with that electrical diagnosis.
P.S. You should install "wing nuts" on those carbs for faster removal.
 
JD....emulsion tubes...nozzles...yes you understand which tubes I am talking about.
These are brass, right? They have been known to crack at the top. Cracks will cause the carb not to pull fuel.

Spin them wing nuts off....and re-check.
 
After installing the freshly cleaned carburetors, 4 new spark plugs, and 4 new ignition coils, she is now running like a champ with the throttle adjusted to the correct position and all 4 cylinders contributing as they should. Idle is nice and smooth as it should be. Still just a little rough sometimes as it's climbing through the rpm range but I'm hoping some of that will clear up after I do a proper break-in and the motor has run for a while. I'd like to thank you guys for all the help. There were several small issues that were contributing to the problem and I learned a lot thanks to all of your help. Thanks again guys.

Thank you
JD
 
And I did find that the nozzle/emulsion tube for cylinder #4 was clogged. I made sure that carb cleaner would spray through each of the passages easily so that I knew the carbs were perfectly clean. After it ran for a few minutes it developed a misfire that is consistent enough to set a clock to. And it's causing cylinders 1 & 3 to blow the fuel recirculation tubes off the side of the block where they slide on to the nipples. The timming light blinks fast and constant until the misfire happens and then it blinks at about half speed for a second or two then back to normal. It does this on all cylinders but only 1&3 are blowing the fuel recirculation lines off. Not sure what's causing this issue just yet but I have to sleep now for work tonight. I'm hoping it's a power pack issue or something. Any ideas on this one? Lol. Fix one issue just to find another.
 
JDBOXER02 said:
After installing the freshly cleaned carburetors, 4 new spark plugs, and 4 new ignition coils, she is now running like a champ with the throttle adjusted to the correct position and all 4 cylinders contributing as they should. Idle is nice and smooth as it should be. Still just a little rough sometimes as it's climbing through the rpm range but I'm hoping some of that will clear up after I do a proper break-in and the motor has run for a while. I'd like to thank you guys for all the help. There were several small issues that were contributing to the problem and I learned a lot thanks to all of your help. Thanks again guys.

Thank you
JD
Click to expand...

WTF? What did you do?
 
Cleaned the carburetors. Lol. Cleaned everything very thoroughly one last time. I did find some stuff that was clogging the carbs. I was under the impression that the emulsion tubes were just the larger diameter tubes with the holes in them. I didn't realize that the smaller tubes inside of the larger tubes were actually tubes, so they didn't get looked at anywhere near close enough during the rebuild. Any ideas on the misfire?
 
Ok so this morning afterni got home from work I decided to mess with the motor again and see if I can pinpoint the issue. Here's what I found: Engine will start and run good for a few minutes but will quickly start to kick and misfire. It's usually bad enough to stop the motr dead in it's tracks, similar yo being hydro-locked on one cylinder, but that's not what's happening. Anyhow, with the timing light hooked up I got the exact same reading from all 4 cylinders. It will flash fast and steady for 5-10 seconds and then the flashing drops to half speed for 5-10 seconds. All 4 cylinders do this and is the reason why the engine will run fine then goes to ****, then back to fine, etc. I gotta get it to fire correctly on all cylinders at the same time, obviously. What can cause this issue? Timer base? I wasn't able to get the DVA meter from work to test the ignition system. What do I do now?!
 
Just go to cdielectronics.com and follow the diagnostics as best you can with the ohm meter, you may find the problem........I might suspect the timing base too or a magnet problem? This may be the problem that messed up your motor to begin with. You have lots of time and money invested here. If you replace the t-base, stator & packs. It might be worth it. Maybe get a second mortgage or something.
 
I'll do what I can with what I've got. It'll be a few days before I get another day off work and will have a chance to actually work on it. I'll post what I find. Thanks.

JD
 
I know this is an old post, did you solve your problem?
Because I'm having the same problem with my 1980 140 evinrude, having to advance the timing too much just to get it to run at idle.
Also you voiced concern that your idle jets were larger than called for. The idle jets on these carbs allow air to mix with the gas instead of the mid and high which gas runs through. So larger idle jets will let in more air so less gas to air mixture, is desired for higher altitudes operation. There is a omc engines bulletin on recommended orific sizes for higher altitudes.

Well I like you am now going to focus on finding a no power cylinder by disconnecting plug wires one a a time while idling as you did but i am waiting on some insulated nylon electrician pliers to do it. Then I will focus on the fuel and reed systems for that cylinder.
 
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