1981 Evinrude 140 cutting out and stalling

[Hunt140]

Hey guys I have a 1981 evinrude 140. I had it out today and I was running it at 4000 rpms for ten minutes or so and then opened it up to 5000. It ran for 10 seconds and then just completely died. Started it back up and had a little trouble but it started to run fine. Shut it off and fished for a couple hours and then ran another 10 minutes at 4000 with no problems. Fished for an hour and then decided to go back to the dock. It picked right up to 4000 and then as soon as the boat planned out it surged and dropped a cylinder. When this happened my tach started going all crazy bouncing up and down. It kept doing it so I had to limp 10 minutes back to the dock. It kept surging the whole way back, sounding like it was dropping cylinders and then picking them back up and dropping again.

I'm almost 100 percent it is electrical because I've been through the carbs and the primer ball is always hard. I'm running out of portable tanks also. It seems like once the electrical componets get hot they start to act up.

Does anyone have any ideas? I'm getting tired of dealing with this thing. I've had it for 6 months and it's just problems after problems. Thanks for any help guys.

 

[Sixmark]

Re: 1981 Evinrude 140 cutting out and stalling

It's not uncommon for coil packs and power packs to act up and/or fail once they get warm if they are bad, but then it could also be another host of issues. The key is to recreate the problem and then conduct testing when it is acting up.

Get it warm enough to where it acts up and perform a spark test and see if you notice a cylinder dropping off.

 

[Sav_Redfish]

Re: 1981 Evinrude 140 cutting out and stalling

sorry

 

[emdsapmgr]

Re: 1981 Evinrude 140 cutting out and stalling

It's either a fuel or spark problem. Probably easiest to check for spark first. Put an inductive timing light on each plugwire when the engine is acting up. Read the spark quality in the flashes from the gun. You will be able to see no fires, misfires and weak spark. Try to determine which plugs are acting up. That engine has two powerpacks, one for each cylinder bank. If you think one bank is acting up, swap the powerpacks and see what happens. Weak ignition components tend to act up when they heat up to normal operating temps. May run fine when cold, then act up when the engine warms up.

 

[Hunt140]

Re: 1981 Evinrude 140 cutting out and stalling

Does the during part when it runs at 5000 make any sense? Is there a chance it could be a sensor or is it leaning towards a powerpack or coil?

 

[Sixmark]

Re: 1981 Evinrude 140 cutting out and stalling

I'm not sure which sensor you would be referring to that would cause this, however these motors are not that complex, as stated before check for spark when it starts to act up and find out if it is actually a spark issue. If it is then swap two coil packs around and see if the problem swaps cylinders when you do it.

 

[emdsapmgr]

Re: 1981 Evinrude 140 cutting out and stalling

That engine has the following ignition components: four spark plug coils, two power packs, a stator and the timer base (sensor.) Any of them can cause an ignition problem. You need to determine which plug(s) is/are missing and go from there. You can swap a spark plug coils to see if the problem moves with one of the coils. Ditto for the two power packs, they can swap from side to side to see if the problem moves with that swap. The spark plug coils are usually pretty reliable, unless a ground has gone bad or you can see some arcing through a crack in the coil. The remaining 3 items are all pretty expensive, so it will pay to do some troubleshooting before you start to replace parts. An original factory manual has a really good troubleshooting section-you can get one from Ken Cook Co. in Milwaukee.

 

[Hunt140]

Re: 1981 Evinrude 140 cutting out and stalling

Alright thanks for the help guys. By sensor I meant the timer base. I guess it's time to do some troubleshooting. I guess if the coils and powerpacks checkout okay it is the sensor? Does this motor have four sensors or two?

Where is the tach wired into? As soon as the motor started acting up my tach went all screwy.

 

[emdsapmgr]

Re: 1981 Evinrude 140 cutting out and stalling

The timer base has the sensor inside which magnetically senses crankshaft timing rotation. It is replaced as one pc. The tach is not driven off the ignition side of the electrical system. It is driven off the battery charging side of the electrical system. The tach counts pulses from the rectifier assembly, which sends DC voltage to the battery. It is common for the tach to start to act up when the rectifier is malfunctioning. If the ignition problem correlates exactly to the tach acting up, you could have some short of short in the stator-between the ignition coils and the charging coils.

 

[Hunt140]

Re: 1981 Evinrude 140 cutting out and stalling

Alright so where should i be looking first? Let the motor warm up until it starts to act up and then check each wire with a timing light and go from there? If it is just one coil or a power pack that is bad would it cause the rectifier to get messed up? Im just trying to tie this all together to get the best idea of what it could be.

 

[dwco5051]

Re: 1981 Evinrude 140 cutting out and stalling

Had a 91 175 with similar symptoms two years ago. Turned out to be a wire coming from the rectifier shorting to the engine block due to some frayed insulation. Only would happen when it got hot. A bad rectifier can cause overheating of the stator Assembly causing other ignition problems.

On a motor this old the first thing I would do was a check of all connections and wiring for bad or loose connections and shorts. Then as other posters have said do a systematic check of all the other electrical components including your ignition/start switch. You are looking at some expensive parts to just guess and change.

 

[emdsapmgr]

Re: 1981 Evinrude 140 cutting out and stalling

Yes, that is a good plan of attack. Normally, rectifer problems are not related to issues with the power pack or spark plug coils. I would agree with dw, that it is prudent to check all the wiring, even going so far as to remove all the grounding wires to the block, clean them and retighten them. Coils, power packs, etc.

 

[Hunt140]

Re: 1981 Evinrude 140 cutting out and stalling

I have already taken off and cleaned the ground for the powerpacks and coils. I also took apart, cleaned and then di-electric greased all of the plug in type connectors. I am positive my coil and powerpack grounds are solid so what else should I be checking?

I'm going to look at the rectifier and wires to see if the wires are in good shape. If the rectifier is bad and starts acting up when up it will cause the tach to 'bounce' and it could heat up the stator causing ignition problems, correct? Is there a way to test a rectifier?

 

[Sixmark]

Re: 1981 Evinrude 140 cutting out and stalling

Have you done a spark test yet? as you seem to be bypassing that part of the diagnostic. Looking for a quick fix for a problem will often cause you to skip over the actual problem.

 

[Hunt140]

Re: 1981 Evinrude 140 cutting out and stalling

No I have not checked anything yet. I am going to start at the coils and go from there. I am just trying to come up with other things it may or could be if the powerpacks and coils checkout okay.

 

[nymack66]

Re: 1981 Evinrude 140 cutting out and stalling

Quick visual check, use a flashlight and look up under the flywheel, if you observe brown melted epoxy like stuff dripping down then your stator is shot and breaks down when heated hence shutdown at WOT, (I wish I had a picture for evidence) If you are replacing the stator then replace the trigger whilst u under the wheel.
I spent a lot of money and time wasted during my rookie months of ownership with mine.
Of course there is a more elaborate and complicated testing that can be done, it however is up to you.
CDI website has a PDF with details instructions in regards to testing.

 

[partybargeguy]

Re: 1981 Evinrude 140 cutting out and stalling

I also have a 81 Evinrude 140 that had the EXACT same issue you have but last year on mine. It drove me absolutly mad trying to figure it out. I am an electrical/electronics troubleshooter by trade and they are fairly simple ignition systems but it really sent me looking.
I hooked multi-meters, an oscilliscope, timing light, etc but the issue would never pop up while I was checking it. It is also not easy, safe, or practical to run WOT and test an outboard behind a pontoon boat.
If I pulled it out and tested it at home it was fine. put it back in the lake and good for a little while then the cylindres would start to shut off.
Anyway to make a long story short it started as specific cylinders not firing so I went down the swap the powerpack/coil/plug/plug wire path but it was still there. Figured out it was random cylinders dropping out (sometimes). Ended up replacing the timer base and all is well.

Well that was a long story but I spent all summer saying not so nice words to the engine but it is once again my friend.

Hope you figure it out, I know how you are feeling.

 

[nymack66]

Re: 1981 Evinrude 140 cutting out and stalling

I also have a 81 Evinrude 140 that had the EXACT same issue you have but last year on mine. It drove me absolutly mad trying to figure it out. I am an electrical/electronics troubleshooter by trade and they are fairly simple ignition systems but it really sent me looking.
I hooked multi-meters, an oscilliscope, timing light, etc but the issue would never pop up while I was checking it. It is also not easy, safe, or practical to run WOT and test an outboard behind a pontoon boat.
If I pulled it out and tested it at home it was fine. put it back in the lake and good for a little while then the cylindres would start to shut off.
Anyway to make a long story short it started as specific cylinders not firing so I went down the swap the powerpack/coil/plug/plug wire path but it was still there. Figured out it was random cylinders dropping out (sometimes). Ended up replacing the timer base and all is well.

Well that was a long story but I spent all summer saying not so nice words to the engine but it is once again my friend.

Hope you figure it out, I know how you are feeling.

Ditto to this..Electronics can be complicated adding heat and moisture/water to the equation certainly does not help!