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1980 Evinrude 140 Idle issues. HELP!!!

J

JDBOXER02

Member
Just overhauled engine and has good, equal compression on all four cylinders. All four cylinders are getting a solid spark(jump 7/16" gap). Motor is running 4 degrees BTDC at 750-850rpms. The problem I'm having is getting the idle set correctly. Right now I have the throttle linkage adjusted so far that the idle adjustment screw is maxxed out and is still half an inch away from the block. I had to adjust it so far in order to get it to idle at 750-850rpms(In a test tank). If I back the linkage off any then the motor stalls and dies. The issue is that it shouldn't have to be adjusted so far in order to idle. I'm wondering if I possibly have a fuel problem that isn't related to the fuel pump or the carbs? Fuel pump is rebuilt and works perfect(pumping primer bulb changes nothing). The carbs were also rebuilt and cleaned very meticulously. Each and every single jet was removed and cleaned, all passages blown out with compressed air, etc. I'm curious about this fuel recirculation system and if there is a way to test it? It has all new hoses and all the check valve w/screens were cleaned out and tested during engine assembly last week. I may be WAY off with this guess and that's fine, I just want to get my motor running properly so I can take it to the lake and do the proper engine break-in procedure. Also, this motor has never ran since I've owned it. Bought boat, motor, and trailer as a project last summer and the motor is all that I have left to complete. Therefore I have no idea if any of the settings were correct prior to me purchasing the boat. I have an OEM manual as well and followed the instructions for setting the idle but it just didn't work out like it was suppose to. Any help or advice will be greatly appreciate! Thank you!


Thanks,
JD
 
Yes. Sorry I forgot to mention that. I did verify that they are all firing and all in the correct place. I even swapped each side, one at a time, to double check. When I swapped them it wouldn't even start and would backfire every few turns of the engine.
 
It's not so much that it idles rough, it's just that the idle is adjusted so high that it should be running a lot higher rpms than just a base idle of 750-850rpm's. It just seems like it's not getting enough fuel to run properly at the correct idle settings.
 
I guess I can run it after dark and use my timing light to look into the carbs and see if I'm getting a good amount of fuel droplets from each carb.
 
JB....this is going to be a long post.

I don't know if the light bulb has gone ON with regard to how this stuff really works.
I don't know if this will clear it up at all or not.

Let me explain myself. Consider this hypothetical scenario:

Remove the linkage that connects to the timer base. Now you have a free floating, free turning timerbase under the flywheel. If you start the engine at this point, and use a timing light, you will observe a timing value. Some timing value, we don't know. Now, if you manually rotate the timer base counterclockwise, that observed value will change.
What will it change to? Well, since you are rotating counterclockwise, you will be advancing the timing, for sure.

But what will it change to? What value? It will change to a value based on the TBs position relative to the crankshaft.
If it WAS 10* BTDC, and you rotate, by chance, exactly 5* counterclockwise, then the timing will be 15* BTDC.
If you rotate the timerbase 5* clockwise, then well...it will be 5* BTDC.
If you rotate the timerbase 20* clockwise, the timing will be 10* ATDC. Remember we started at 10* BTDC.

So, what is my point? My point is that you have the timing (timerbase) positioned perfectly at 4* BTDC.
Wherever that timerbase is sitting, it is producing a timing of 4* BTDC.

It is all in the position of the timerbase relative to the crank. And of course the geometry fact that there are 360 degrees in a circle (one revolution of the crank).

Now. You got the timerbase at 4* BTDC. The problem is that the linkage is not playing well with that timerbase position. You see what I am trying to say?

If it were me, I would look for maybe a part installed backwards, like a linkage rod, or in the wrong hole...something that would make the linkage all out of whack.

Do you know the timing spec for that motor?....I don't offhand. I am working on a 1985 115 right now, and I am finding the idle timing specs as discussed on various boards and books to be 4* BTDC. So it seems to me that you are close to the exact correct timing value you need. Motors are very similar.

And of course...be sure you are using a factory service manual, because the info contained will be specific to your model number. Trying to do this with a Clymer or Seloc will be a real trick.
 
Daselbee,

I am using the OEM factory service manual specific to my model number E140TRLCSA. Timing is either 4*of 5*BTDC, don't recall off the top of my head and I'm at work right now. I actually just had this discussion with a guy at work and more or less had a "palm to the forehead" moment as I was actually explaining to him how it all worked. I realized that if the timing was 4*BTDC when rotated counter clockwise as far as it currently is, then the timing has to be off when the throttle is at it's correct resting point. Now I must go home in the morning and figure out why the timing is off. Thanks so much for your help. I will post what I find and the results of fixing it.

Thanks,
JD

PS. I love this forum!
 
If I were to venture a guess, it would be that the flywheel has rotated out of position on the crankshaft. I say this because I recall thinking to myself that the woodruff key that holds the flywheel in position seemed to have a bit of wear on it. I'll check this first thing in the morning and post what I find. Thanks again.
 
First and foremost allow me to apologize. I was mistaken about some of the previous information I provided when describing my issue. So it turns out that with the throttle advanced as far as I've had to advance it in order to get it to idle, it is actually running at 12*BTDC. With the throttle in it's correct idle position it is running 4*BTDC but he rpm's are so low that the engine stalls. So the question remains, since the timing is correct, flywheel is in the correct location and timing light verified, why will the engine not run the correct rpm's?! Once again this is my first outboard and I'm still learning. Thanks for the help guys!

Thanks,
JD
 
OK, so linkage at idle position, timing light flashes and indicates an approximate timing of 4*BTDC.
Right?
But engine idles so slow it dies. (or never even tries to idle).

So, verify please....all butterflies are fully closed at this idle position. Correct?
If the above is the case, I would look at the possibility that it is not running on all four cylinders properly.
You may have spark on all four, but is the spark happening at the right time in the piston cycle? TDC.

So, a way to tell this is to mark the flywheel with white mark at TDC for all cylinders. Called indexing the flywheel.
There will be four marked places, each spaced 90* from each other all around the outer rim of the flywheel.
It doesn't really need to be EXACT for your purposes.
I always put one white mark at tdc for #1, two white marks at tdc for #2, three white marks at tdc for #3, and so on. They can be just dots.
I use white fingernail polish.
Set the timing light up, observe flash and single mark for #1. Then move timing light to #2, and observe 2 marks lit by the flashes.
Check all four.
If the cyls are not firing correctly, while you are on #2, you might see four marks...see?
That would cause two cyls to not contribute to the running of the engine.
If they are not right, look at the coil primaries being swapped onto the wrong coils. Very easy to do on these crossflows.

If that all checks out, you must look into why the carbs are not delivering enough fuel to keep it idling.
One possibility is the center nozzle o-ring gasket missing from all carbs.
There are other possibilities of course.
 
Yes linkage at idle position shows 4*BTDC but stalls out and won't idle. In the process of indexing the flywheel now and noticed, by the flashes of the timing light, that there appears to be intermittent misfires on multiple cylinders. I'm gonna continue verifying that each cylinder is firing at the correct time then I'm gonna go from there. I'm gonna use my meter to check the power packs for faulty isolation diodes too.
 
Ok, indexed flywheel with marks 1-4. With timing light on cylinder 1 it would flash on the #1 mark bit there were a couple of times when it would also flash on the #3 marks. With timing light on cylinder 2 it would flash on both #2 and #4 marks. With light on cylinder 3 it would flash on #3 mark intermittently and with light on cylinder 4 it would flash on #4 mark intermittently.
 
JDBOXER02 said:
Ok, indexed flywheel with marks 1-4. With timing light on cylinder 1 it would flash on the #1 mark bit there were a couple of times when it would also flash on the #3 marks. With timing light on cylinder 2 it would flash on both #2 and #4 marks. With light on cylinder 3 it would flash on #3 mark intermittently and with light on cylinder 4 it would flash on #4 mark intermittently.
Click to expand...

OMA! What a result!! (Anybody get that "oma" joke?)

Wow....swap powerpacks side to side. See if you get the exact same results. If you get the same,
then you likely have a bad timerbase.

Testing a powerpack with an ohmmeter is not reliable.

If you look into the timing light while running...you MUST get solid steady flashes.
Everything has to be solid and steady...no multiple cylinders showing...etc.
 
Ok. I'll do that now. The timing light would give me solid steady flashes for 45-60 seconds then would skip a few times etc. On cylinder 2 it stayed flashing steady thw entire time, never missed a single time BUT would show to be firing on index marks 2 and 4 on the flywheel while running. Weird I know but I'll go do it again right now and swap power packs then post the results.
 
I'm gonna have to stop working on this motor after pulling 17 hour shifts on only 3 hours of sleep. I'm making simple, rookie miatakes and wasting everyone's time. Ok so here's the deal. I was wondering why when the timing light was on the top cylinders (1&2) it would show to be firing at index marks 1&3 and 2&4 but it wouldn't show to be firing that way when the timing light was hooked up to the bottom cylinders (3&4). What I discovered was that it was my own dang fault. When I hung the timing light clamp on the spark plug wires for 1&2 the clamp would come to rest against the ignition coil for the cylinder below it. This was enough for it to pick up the signal from that coil and give me the false reading of firing at the wrong time. I didn't notice this at first because I was holding the timing light on the front side of the motor with one hand and using my other hand to cast a shadow on the flywheel in order to better see the timing marks. After realizing this I resolved the issue and discovered that I was still getting intermittent spark on several cylinders. I swapped out all 4 ignition coils with ones I knew to be good off my Johnson 150 (same part#) and the intermittent spark went away but the engibe isn't running any better. I tested the spark with a gap tester set to 7/16" and all showed to have a strong blue snap of a spark and the timing was correct for all cylinders. So then I decided to pull each plug wire, one at a time, to see if I had a cylinder that wasn't contributing. Results were that 1-3 caused the engine to fall on it's face, even worse than it already was, but pulling the wire on #4 made no difference. So I did another compression test and all cylinders have 130-133psi. I also noticed that the plug for #4 did have oil and fuel on it as to indicate that it was at least getting some fuel. So what would cause this cylinder to not contribute if it has solid spark, correct timing, and good compression?! And would one cylinder be enough to cause the idle issues to be as severe as they seem to be? By that I mean having to adjust the throttle linkage so far just to get it to idle at 750-800rpms. It should be running over twice those rpm's when the throttle is in that position. Also the motor seems to be getting hotter than it should for being in a test tank of constant flowing fresh water. The water pump is new as well and is pumping like crazy. There are no clogs in the cooling system and the water exiting the engine is barely warm at all but the cylinders are getting too hot to touch. To me this indicates a lack of oil and fuel. Help! Thanks for your patience and your help.

Thanks
JD
 
#4 must be running cooler than the others if its not doing its job. Simple.......maybe a bad spark plug? One cylinder with no ignition CAN cause your idle problem, yes. If your given info is correct, everything has been pretty well covered.
 
Another thought, why was the motor overhauled and what is the piston to cyl clearance??? It must have been bored, right? If there is not enough clearance it will run hot and the engine will drag, causing your idle speed problems. When it is warm, take out the plugs and see how hard it is to turn by hand.....always turn it clockwise.
 
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Engine was overhauled because #4 broke a ring. The piston was damaged and head was damaged but since the ring only broke off a small piece, it didn't damage the cylinder walls. Therefore there was no bore needed. The cylinders all had less than .001" wear and pistons 1-3 looked like new and measured out the same. Cylinder 4 has a new piston and rings while cylinders 1-3 have new rings. All pistons were decarbed and everything was measured and done in accordance with the manual and factory specs. All cylinders have 130-133psi. With engine warm and plugs out it turns easily by hand.
 
It would only run cooler if it wasn't doing it's job but was getting the proper fuel and oil, right?! No lubrication from fuel/oil would cause an increase in temp. Right?!
 
Well.....don't see any problems with that. You have been very thorough and diligent. I'm stumped, brother.
 
What do you think caused the cracked ring? Maybe a timing issue. Daselbee may be on the right track. Rings rarely break without a reason. Perhaps the spark is coming to this cylinder without proper timing......What do I know? Only been fixing outboards for 48 years.
 
Lol. Well Timguy I've only been working on outboard motors recently. I've been dealing with mechanics, hydraulics, pneumatics, and electronics for 15 years. I'm stumped too. When I tore the motor down I discovered that every cylinder had ring issues. They were all brittle and some had broken rings that just hadn't come out of the grooves yet. #4 was the only one that had the ring break and come out of groove. I am lost on this issue too. The timing indicates that everything is correct. All indexed marks are 90* apart on the flywheel and all fire at the right timefor each cylinder. I've swapped power packs, coils, spark plugs, and nothing seems to help. I refuse to give up, I'm just not sure were to go from here. I'll start all over if I need to. Just need some help with the direction I should head at this point. Thanks guys


JD
 
JD, go to cdielectronics.com and do a complete ignition diagnostics. Follow the procedures as listed, maybe get a DVA adapter for your multimeter or get a new DVA multimeter. Take a couple side jobs to pay for the meter......you can't go wrong by knowing more about electrical diagnostics, you can save people big big money, time, and aggravation. Swapping used parts doesn't always work, brother.
 
I know swapping used parts doesn't always work. The only used parts I swapped were the ignition coils and that eliminated the intermittent misfires as far as the timing light is concerned. All have strong blue spark that jumps 7/16" gap. I will do as u suggested and do an entire ignition system diagnostics. I have a DVA multimeter at work that I can bring home and use or take my boat to work and test it there. I'll try to get that completed over the next few days and I will post my results. If anyone has any other suggestions or ideas, I'm all ears. Thanks for trying to help me figure this out, Timguy. I really do appreciate it.
 
If you have strong 7/16" jump spark, and no misfirings as viewed by the timing light, AND the indexing shows all firing correctly, then in my opinion doing this full ignition analysis will be a waste of time.

That said, what is wrong with it? Hmmmm.

Try to get it running long enough to spray pre-mix in the carb throats. If it is running starved for gas at idle, it might pick up.
If it is not getting fuel air mix from the crankcase, then it will not do anything.
Also, you can turn the red lever of the primer solenoid until it dribbles fuel into the primer lines.
This will supply fuel to the engine....very rough, not finely metered fuel, but rough supply, that might tell you if the engine is starved for idle fuel.

You DO have the bowl gasket on the carbs installed, with the nozzles thru the proper spot on the gasket, and no tears or crushed "nozzle loop", right?

Look at parts pages carburetor section #10 reference number. I assume you know how to get to the parts pages.

The following might not be correct for your carbs. I don't know them well, but see if it applies:
There are brass tubes extending into the bowl from the upper carb body. Two tubes, each consisting of a tube in a tube.
A small tube inside a larger tube. That small tube is the idle fuel supply tube, and MUST be clear.
 
Daselbee, I did not do the premix in a spray bottle and spray it into the carbs but I did flip the primer solenoid lever slightly over to the manual side and it greatly increased the rpm's of the engine. The bowl gaskets are installed correctly and the tubes that u are referring to are Emulsion tubes and are, or were clear. I'm pulling the carbs off and going through them again. From the beginning I've suspected a fuel supply problem but didn't check into it enough. I also mistakenly privided y'all with incorrect information that lead me in other directions, but that is nobody's fault but my own. I agree that with solid spark and no intermittent firing, testing the ignition system is probably a waste. I'll post what I find with the carbs. Thanks again.

JD
 
Ok, tearing the carbs down and found something that I'm curious about but not sure how much of an issue it can cause. First of all, everything is very clean and looks to be just fine. But I was pulling the jets out to make sure they are all cleaned and if you pull up the carburetor print for E140TRLCSA you will see item #7 is an orifice that is at the top side of the carb and is a No. 25 for the 140hp. The ones I pulled out of mine are a No. 27, which are more along the lines of what is called for on a 100hp motor but I'm not sure what difference it would really make on my motor. The intermediate and high speed jets are all correct, No. 29 and No. 67c. And apparently the small tube that sits inside the larger emulsion tube is what feeds this jet for the idle. Which would indicate that the idle jet is actually a little larger than it's suppose to be. I'm having a fuel supply problem and the jets are bigger then they're suppose to be? Lol. Awesome.
 
Alright now the carbs are completely redone and I can say with absolute certainty that there are no plugged orifices, passages, tubes, or anything else! I will reinstall them on the motor in the morning and see what happens.
 
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