Power issue 40 HP 1985

[Phil70]

Hi everyones,

Sorry if I made some mistakes but english is not my native tong.

I bought a little boat last year with an outboard E40RCOB of 1985.

At the begining, no trouble, the engine was just fine.
After few weeks, no spark, I ask to a pro to look at my engine and the power pack has been replaced by a new one, but crashed again because all cables from the stator plate were too old and burned.
So I had to change the coil and sensor too, with a new power pack.
Everything seemed to be right with the new ingnition system, the engine starts again without trouble.
I went to the sea to test this but after few minutes, the engine loses completly his power. 5 knots max.
I decided to clean the carburators by myself, and bought two carburator repair kits to be sure.
After that, it was a little better, but only for 30 minutes of navigation.
Now, It can runs without pb around 30 minutes, and my engine loses his power and refuses to take more rpms.
No pb with neutral position, or in my garden, but it's not the same story on the sea.

After all this time, I'm desesperate because I put a lot of money to change all ignition parts (coils, power pack, spark plugs, wires) and renovated all gas circuit (carb and pump repair kits, hoses, fuel connectors, fuel tank). Just for info, I also use two new Champion L77JC4 for this engine.

Another pro here tells me it could be a dilatation of my flywheel ***y when the engine is hot.
For me, this piece seems to be very solid, I don't know.
What do you think about that ?

I completly lost and hope someone had already knew an issue like this, and I can fix it.
Many thanks for your help.

[boats.net]

Have you checked compression to see if both cylinders are even?
Have you checked to see if both cylinder have good spark when engine loses power?
Look at fuel primer bulb to see if it's sucked flat(signs of a fuel restriction), have you tried pumping fuel primer bulb or bumping choke(sign of starving for fuel) to see if rpm's pick up?

[Phil70]

Hi,
Many thanks for your reply.

Yes, I forgot to mention but I checked compressions on both cylinders and it was OK : 9 and 8.5 bars.
No, I didn't check the sparks when the engine gets into trouble, but the motor starts very well, even after power failure, and in the neutral position, the engine runs into max rpms.

I must recheck all the coils with my ohmmeter. Before and after the issue and compare the results.
The only way to see this issue is using this motor loaded and on the water.

I replaced all the pieces between the tank and the carburators.

The gas pump just after the tank stays hard, and nothing better happens if I pump it when I get the issue.
I also changed the primer pump because it was very hard to use, this part looks like a starter, used to pull gas directly into the carbs, just to have a better cold start.
and if I pump this primer, the engine stops because on this first action, the gas is sucked and leave the carbs, I think it's normal, nothing bad here.

I cleaned the carbs three times, with Evinrude special products.
I also cleaned the leaf plates and changed the paper gasket.

This issue appears when the engine runs after 30 minutes, when it's heating up.

Many thanks for your help

[Joe Reeves]

This test will eliminate the "Kill Circuit" and make it impossible to stop the engine via the ignition switch, so be advised that momentarily you'll need to stop the engine by flooding it out or some other means. Also be aware that touching the metal portion of the mentioned black/yellow wire will give you a nasty shock. Test is needed as before the cause actually damages the powerpack, it'll make the engine have weird encounters.

Simply remove the black/yellow wire from the ignition switch or the same wire leading to the powerpack (whichever is easier). If the problem ceases to exist, that indicates a internal short exists within the ignition switch that is supplying actual battery voltage to the powerpack... in which case, replace the switch.

Additional info follows:
*************************
Voltage To Powerpack Failures
(Magneto Capacitance Discharge Systems)
(J. Reeves)

The usual cause of having those type powerpacks fail repeatedly is having a very small of voltage applied to the Black/Yellow wire (Kill Circuit) at the pack. Test as follows.
Disconnect the Black/Yellow wire at the powerpack.

Insert either a ampere meter or a volt meter set to its lowest DC voltage reading between that Black Yellow wire and ground.

With the ignition key in the OFF position, observe the meter reading. Now turn the ignition key to the ON position and again observe the meter reading.

Any reading, movement of the meter needle, even a microvolt, would indicate that battery voltage is being applied to that Black/Yellow wire. If a reading is present, remove the other end of that Black/Yellow from the raised terminal of the ignition switch.

If the reading ceases to exist when the Black/Yellow wire is removed from the ignition switch, replace the switch. If the reading continues to exist, there would be a short of some kind in either the engine or instrument wiring harness.... to determine which, simply unplug the large RED electrical plug at the engine which would eliminate the instrument cable.

Note that the black/yellow wire must not have any other wire attached to it for the following reason!

Keep in mind that any accessory that has 12 volts running to it, especially when turned on, will have voltage flowing thru it and trailering out thru its black ground wire to complete the circuit. If that accessory has it's black ground wire attached to the "M" terminal that the black/yellow wire is attached to.... you will have voltage flowing directly to the powerpack.
********************

[Phil70]

Hi and thank you for your advises.

My motor has a rope, and no battery of course, but I can do all test by this way, it works too, I already used it to check ignition sparks :
I take off the rope start system and the spark plugs, connect the spark plug wires to the ground, and put a screewdriver on the top of the crankshaft to simulate an electric starter.
Can I do the same test in this case ?

Waiting to read you, thanks again.

[Joe Reeves]

Disregard my reply via post reply #4.... It is a test to see if a ignition switch is faulty which you do not have. Sorry.

[Phil70]

You don't have to be sorry, I never mentioned this detail.
You advised me about ignition system, so I think I must check this part carrefuly.
Can you confirm me the right voltage or best values I must found for this engine ?
Do I must buy a DVA adapter for this ?

Thank you

[Phil70]

one more thing :
When the engine loses his power, sometime, not all the time, the engine relives again
with all its power but after few minutes, fails again.

It's very disturbing.

[Joe Reeves]

Check the stator under the flywheel to see if it's melting down. The stator delivers approximate 300 AC volts to the powerpack capacitor, and when/if the stator overheats and starts to actually melt down... drips a sticky looking substance down on the powerhead area, it may function when cold BUT when hot, it'll supply weak, erratic, and eventually no ignition. Check it!

[Phil70]

Before buying some tools to take off the flywheel :
I checked statically the charge coil : 558 ohms (yellow-brown, brown wires before the power pack)
sensor : 49 ohms
and to be sure, the two high voltage coil : 318 and 1 ohms on both

I put an electric screwdriver on the top of my crankshaft to simulate an electric start, trying to check dynamicly the charge coil : not stable, I had between 32 and 38V AC.
I also checked the sparks, around 1 cm long on my tester but the sparks are not so synchronized, not very good tempo, I don't know if it must be synchronised all the times, maybe because I also don't have a stable voltage from the charge coil.

What do you think ?

[Joe Reeves]

I just checked my 1985 40hp parts book to re familiarize myself with your rope model E40RCOB and its ignition components. I DO NOT have the service manual on that engine and cannot rely on memory as far as the voltage or ohm readings, however.............

If the charge coil that supplies AC voltage to the powerpack (has 2 wires (Brown & Brown/Yellow) does not coincide with the service manual as far as the listed ohm and voltage readings... replace it. And should it be oozing any substance from it, replace it regardless of whatever reading you may get from it.

With the spark plugs removed so that you can obtain the highest cranking speed with whatever method you're using.... same speed as the momentary rope pull speed BUT constant.... the spark should be a strong blue lightning like flame that will jump a 7/16" gap... a real SNAP... and steady as long as the flywheel is turning at the proper speed.

NOTE... The 7/16" gap is important... nothing less will do!

That's what I think. Let me know what you find.

[Phil70]

Hi Joe,
Many thanks for your reply.
If I look at CDI Electronics electrical trouble shooting guide, the resistance results are OK but coil voltage, tempo and gap for sparks seem to have poor values.
We can read on the guide : a cranking speed of less than 250-RPM will not allow the system to spark properly.

If my inch conversion is good : 7/16" is 1.11 cm for me.
I'll check it again with a more powerfull screwdriver, trying to get a better simulation.

[Phil70]

Hi, Please, take a look at the link here to see the sparks I have : https://drive.google.com/open?id=1kL...jMMi2nO9_S7D4J
It's bad, isn't it ?

[Joe Reeves]

Originally posted by Phil70 View Post

Hi, Please, take a look at the link here to see the sparks I have : https://drive.google.com/open?id=1kL...jMMi2nO9_S7D4J
It's bad, isn't it ?

Apparently, whatever format is used in your video... it is not covered in my computer and I do not want to become involved in downloading programs that might conflict with what I use, sorry. You'll have to be the judge of the sparks quality... or a more knowledgeable friend if you have doubts.

[Phil70]

Hi Joe,

Sorry for the delay of my response but I never received a mail notification of your post from the forum.

The delay of conversion of Google drive can be long, sometimes one hour, sorry.
If you retry to watch Google videos after few time, it'll works.
Now, it's possible to see the last video online without pb, conversion was done by Google.

For the record, I changed the charge coil last week.
It was already replaced by a professional last year, but as I said it was an old stock product, maybe not so new or not so good, and not so well mounted by the pro too.

Please, take a look at the little video I made to see and compare the result, (it will works online, no doubt, conversion is already made) :
https://drive.google.com/open?id=1Ig...3kqSs-BeLZAc1B

I think the issue is solved.
I tried the engine in my garden, and it started very well and the motor is more powerfull, I'm very happy.
In few weeks, I have to take the sea to confirm the repair but I'm confident.

Many thanks for your support.