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Evinrude 1970-1980 running bad

DrCoxie

Contributing Member
Hey there, I have a question to anyone who is willing to answer, I've been working on my 15 hp evinrude (like 1970) or so, and ive fixed the foot which had a problem with the clutchdog cradle and now im working on the powerhead; my issue is that it either doesnt get up to high rpm or doesnt want to start, i have to adjust the mixture screw for running well at a higher throttle setting (leaner mix) and being able to start it (fat mix) worth mentioning it doesnt idle without giving it a fair bit of throttle. Ive cleaned the carb and it seems to work fine as far as I can tell, I've suspected the electical but i got spark on both cylinders so not that either.the fuel pump ive ordered a rebuild kit for, i suspect it a bit **** and ive had bad luck with leaky primer bulbes. What i'm wondering is if these symptoms are indicative of something I haven't thought of, a mechanic who looked at the engine told me compression is fine as well and can hear the pressure when i spin the flywheel. Can a bad pump cause the engine to be hard to start and having to adjust the mixture manually in order to get it running well? Do I need to look at the carb again? Been working on this for a year now and learned as I went and I'm getting slightly frustrated. Also worth mentioning is that I ran it on the water and it ran like a dog, didn't even get the small boat I have it on up to plane. Someone got an idea?



 
Sure would help to know what year motor we are dealing with. But a couple of general thoughts come to mind. The carb mixture screw should have very little, if any at all, effect on running at full speed. If you have a 1974-76 model, they are notorious for fouling spark plugs. Even new plugs with very short run time on them. That certainly would account for your hard start / no power problem. Have you tried new ones of the correct type? Yeah, I know there are a lot of opinions on what are the correct or best type.
 
Yeah I'm sorry I forgot what year it was, I think I figured out it as a 1974 once but I'm not sure, I'll update when I find out for sure but thanks for the tip, it's much appreciated. I ordered some plugs bcs I thought it was a cheap insurance, the plugs have been in there for years as far as I know and the engine has been sitting for a good while. I ordered two B9HS from NGK bcs that's what was in the motor but if you know of something better id gladly try something else out. Edit: not trying to make you work for me, I've looked around and tried hard to find a more modern set of a plugs or compatible types that are more available (had to order online because none of the stores around where I lived had this type) but I couldn't find anything save a huge list of plugs that apparently were compatible but no information on whether they were better https://www.sparkplug-crossreference.com/convert/NGK_PN/B9HS here it is, not sure what to do with it xD

I should clarify, its not WOT i'm talking about since the engine doesn't allow for that in neutral gear, its just as far as i can twist the handle while out of gear and it seems to hit a nice groove when i set the mix lean but thats at max throttle in neutral, as soon as i let off it starts wanting to turn off and when I go to zero throttle it just has zero chance of running, it just stutters to a halt. I suspected the power pack or coils for a while but since it runs so well in that state I figured the electrical is fine (save the plugs maybe)

Sure would help to know what year motor we are dealing with. But a couple of general thoughts come to mind. The carb mixture screw should have very little, if any at all, effect on running at full speed. If you have a 1974-76 model, they are notorious for fouling spark plugs. Even new plugs with very short run time on them. That certainly would account for your hard start / no power problem. Have you tried new ones of the correct type? Yeah, I know there are a lot of opinions on what are the correct or best type.
 
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I put tons of money and hours in my engine.... A single 2 month old plug that died caused it all to go to hell.... Check that no air is getting in the carb or system...
Make sure you do a very good job on the carb.... Start at 1.5 turns out from closed on the needle.
Check your wires aren't arcing to the block... And check the sync with the throttle roller and Cam mark....
Sounds just like what my problem with it was...
Don't assume anything about these engines!
 
Sure would help to know what year motor we are dealing with.

^^^^^ This.

There should be a model number on an identifaction plate on the port side of the transom bracket... If you tell us the model number we can tell you the year and help to better steer you in the right direction.
 
^^^^^ This.

There should be a model number on an identifaction plate on the port side of the transom bracket... If you tell us the model number we can tell you the year and help to better steer you in the right direction.

Okey, I've finally gotten around to finding out what it is after rebuilding the fuel pump and I've got updates on the engine and a few more questions.
So the code I found is E15BACNC and I found a thing telling me to ignore the E and C at the end which would make it a 1982 15 hp Evinrude.

Update: After rebuilding the fuel pump (very much needed the old one was just absolutely trashed) it now starts on its own (not cold start) I had to start it with some starting fluid but after that it turned on very easy on the pull with the right amount of throttle but without some throttle it wont stay running.

Questions:
1.Could the bad idle be caused by bad plugs? because if you can believe it they sent me a cam belt for a BMW instead of my sparkpluggs so I haven't been able to install those.
2. I have previously removed the thermostat bcs it was completely crusted shut and freed up the water passages, I put it back together without a thermostat, I know this will make it run at less than ideal temps but is there any other reason not to?
3. Could the butterly valves be the reason for the bad idle? if they aren't completely tight?
4. I've been also told the crankshaft seals could have gone bad, would that mean removing the covers on either side of the powerhead and installing new caskets or does that involve taking the whole powerhead appart and the crank out?

Also, if I have to do that, does a cheap torque wrench do it (one that just shows the torque on a scale no clicking) or do I need one that clicks?

Sorry for late update I've been working!
 
E15BACNC:

E - Evinrude
15 - Horsepower
B - Belgium
A - ? (Don't recall - Fellow members... What the hell does this stand for?)
C - 8
N - 2 ..... CN=82 = 1982
C - Factory run number, of no consequence

Doc (If that Dr stands for doctor, vet, cardio speciai$t, whatever).... that adjustable needle valve is the air/fuel adjustment for slow speed only and has nothing to do with high speed. You're overlooking something in the carburetor cleaning job. Redo that portion of your work and pay particular attention to the high speed jet located in the the foremost bottom portion of the top body (small brass jet).
********************
(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
********************
 
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E15BACNC:

E - Evinrude
15 - Horsepower
B - Belgium
A - ? (Don't recall - Fellow members... What the hell does this stand for?)
C - 8
N - 2 ..... CN=82 = 1982
C - Factory run number, of no consequence

Doc (If that Dr stands for doctor, vet, cardio speciai$t, whatever).... that adjustable needle valve is the air/fuel adjustment for slow speed only and has nothing to do with high speed. You're overlooking something in the carburetor cleaning job. Redo that portion of your work and pay particular attention to the high speed jet located in the the foremost bottom portion of the top body (small brass jet).
********************
(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
********************

The one screw I have does nothing for strting easier, in fact I just went out to check if ive done smth wrong and now I cant get the engine going at all even with starting fluid. The screw only improved how the engine ran and I believe it was set correctly, the issue isn't the carb or the mixture, something else isn't working and now I'm worried that the stop button has gone to **** and I have to get a new one of those bcs its preventing the engine from running...
 
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