1985 evinrude E20CRCO misfire

[ab59]

I just bought an old 1986 Crestliner 14' aluminum boat with a 1985 Evinrude 20hp motor on it. I put a new water pump in it, some new oil seals on the driveline, and changed the lower oil. It started first pull and ran a bit with no problem then began a heavy misfire or cough. It will clean up every now and then and then start the same again. I pulled the plugs and ran a compression test thinking that since the water pump was not pumping water when I brought it home that the PO may have got it hot and blew the head gasket. Both run about 100 psi. I don't know what is good or bad for compression on this motor. When I pulled the plugs I did notice that the bottom plug had some oil on it while the top plug looked brand new. I do not know how long the boat sat since the last time it was used. The tires are dry-rotted to the point that they only hold air for a couple of days so It might have sat quite a while. Where should I start to look? thanks--

 

[racerone]

Top plug might not be firing.----Fuel pump diaphragm might be ruptured.----Throttle plate might be opening too early.----Low speed mixture might need to be adjusted / opened.---Easy diagnosis and easy fixes.

 

[ab59]

Thanks for your reply. I will take that advice in the order you gave it. I almost went out after dark and pulled the plugs to test for fire in the dark so that I could see the arc better but am smoking a pork butt for the church tonight so it will be ready tomorrow. It does start right up first full pull, no electric starter on this one, and idles fairly good until the cough starts. No problem throttling up either but the cough is pretty radical at higher throttle.

 

[saltchuckmatt]

Get a spark gap length tool. You can get an inexpensive single one for under $10

Check spark for a 3/8 jump with a good blue snap. Most likely bad spark or crap in the carb. Don't run it with high rpm's in a barrel or on muffs.

 

[ab59]

Ok, it looks like the bottom plug is not firing. I hooked up a timing light, hooked it up to the top plug wire and pulled the starter rope, and got good spark from the top plug, but the bottom plug wire is getting no fire at all. I just ordered another power pack. Hope this solves the problem. Thanks for the advice guys, I keep bailing off into things I know nothing about so your advice is valuable to me. thanks again and I hope this will get me crappie fishing in a few days.---

 

[Crosbyman]

could be the pack but something simple like corrosion on the pug end or a broken wire. in a bend

check the ignition primary and secondary resistance

did you interchange spark plugs ... will the firing plug fire on the bad... plug wire if yes then one plug is bad

plug boot the engine ground should show equal continity top and bottom plug wire

 

[saltchuckmatt]

Yes, next time don't just order a part when you haven't tested what's wrong.

Swapping or testing coils, plug wires.....dirty connections, the list goes on.

 

[ab59]

Yes, next time don't just order a part when you haven't tested what's wrong.

Swapping or testing coils, plug wires.....dirty connections, the list goes on.

Oh? Didn't I test the wires for spark and find that I did not get spark from the bottom wire? This is why I ordered the power pack. Was there something else that would cause one wire to be dead? Plug wires are in good condition. No really, am I missing something here? About coils, is there one for each cylinder? I guess I'm used to one coil per engine. I have a repair manual coming so I hope that will allow me to better service the motor. I have done a little carb rebuilding here and there on these older 2 strokes but am just beginning to learn about the motors. thanks for your reply

 

[ab59]

could be the pack but something simple like corrosion on the pug end or a broken wire. in a bend

check the ignition primary and secondary resistance

did you interchange spark plugs ... will the firing plug fire on the bad... plug wire if yes then one plug is bad

plug boot the engine ground should show equal continity top and bottom plug wire

Ok. I must be missing something here. What purpose would it serve to interchange the spark plugs positions if there is no fire to the wire? Wouldn't the wire still not have spark no matter what plug was in that boot? Wires look to be in good condition, I don't see corrosion at either end. Testing the ignition primary and secondary is an unknown process to me and my knowledge of systems is very limited. I did order a repair manual a couple of days ago, hopefully, there will be information on that subject in the book. I can be a little thick-headed when it comes to things I don't understand sometimes. If I'm asking stupid questions it's only because I'm trying to understand the process. Thanks for your reply.

 

[racerone]

With spark lost on 1 cylinder then 99 times out of 100 a new powerpack fixes it.-----Good luck with this.

 

[ab59]

With spark lost on 1 cylinder then 99 times out of 100 a new powerpack fixes it.-----Good luck with this.

Thanks!!!

 

[Crosbyman]

Ok. I must be missing something here. What purpose would it serve to interchange the spark plugs positions if there is no fire to the wire? Wouldn't the wire still not have spark no matter what plug was in that boot? Wires look to be in good condition, I don't see corrosion at either end. Testing the ignition primary and secondary is an unknown process to me and my knowledge of systems is very limited. I did order a repair manual a couple of days ago, hopefully, there will be information on that subject in the book. I can be a little thick-headed when it comes to things I don't understand sometimes. If I'm asking stupid questions it's only because I'm trying to understand the process. Thanks for your reply.

Racerone lilkely correct but finding or narrowing down a problem requires eliminationg section.

not knowing if HV is actually present (generated) it could be a sparkplug or corrosion stopping it from reaching the plug gap. swapping parts helps to narrow things down.

one way to know if HV is present also includes poking a screwdriver in the plug and placing it near the engine frame to see arcing jumps over. In any event let's see what the new pack does.

testing coils with an ohmeter is not complex but requires know how. here is a link on how to test coils of a different older kind but they all basically have a low voltage winding charged up with magnetism from the flywheel that gets reconverted to high voltage on the second (secondary) winding which has one side to ground and the other going to the plug.

utube is your friend. one type of coil

Testing an Outboard Coil with a Multimeter using an ignition coil from the Johnson H or T

Multimeter testing of Johnson outboard coils

www.pochefamily.org

 

[saltchuckmatt]

Oh? Didn't I test the wires for spark and find that I did not get spark from the bottom wire? This is why I ordered the power pack. Was there something else that would cause one wire to be dead? Plug wires are in good condition. No really, am I missing something here? About coils, is there one for each cylinder? I guess I'm used to one coil per engine. I have a repair manual coming so I hope that will allow me to better service the motor. I have done a little carb rebuilding here and there on these older 2 strokes but am just beginning to learn about the motors. thanks for your reply

Yes, there are two coils. Swap them and see if your problem follows.

 

[ab59]

The end result!! It was the power pack. I replaced it today and no more problems. Well other than it does not want to slow idle at all. 3 gal of old gas mixed with 3 gals of new gas and some Sea Foam. I believe the boat sat for a year or more. Going fishing soon and will try to run the gas out and start fresh after that. I intend to run Sea Foam for at least 4 tanks of fuel. Thanks for all the input. I ordered a pair of coils as well. I will install them when they get here. For another 30 bucks, I figured it would just replace all. thanks again.

 

[Crosbyman]

keep old coils as spares !!!!

if they are good .you could keep them in place and store the new ones.

 

[saltchuckmatt]

If you paid $30 bucks for 2 coils than I'm not sure what quality you bought.

I would finish dialing in the motor before I went fishing. Have you done a link and sync?

 

[ab59]

If you paid $30 bucks for 2 coils than I'm not sure what quality you bought.

I would finish dialing in the motor before I went fishing. Have you done a link and sync?

18-5179 Ignition Coil Fits for Johnson Evinrude 6hp 15hp 70hp 85hp 88hp 90hp 115hp 120hp 125hp 1985-2001 Replaces 18-5179 582508 183-2508 Pack 2​

Brand: Waricaca
4.5 out of 5 stars 42 ratings

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[ab59]

If you paid $30 bucks for 2 coils than I'm not sure what quality you bought.

I would finish dialing in the motor before I went fishing. Have you done a link and sync?

I want to run this older gas out of the tank before I begin to tinker with the carburetor. I have a 1986 Mercury 90 hp TOP that could use a link and sync as well. I need a motor manual as well and have not received the one I ordered yet. I'm sure that you are right, the motor has been deprived of maintenance in the past so bringing it up to snuff is a good idea. once again, thanks for all the replies they have helped.

 

[racerone]

These coils are very reliable.-----Plentiful good used ones in my area.----Dealers don't bother to remove them from parts motors that I have picked up.

 

[saltchuckmatt]

Your link didn't really work but the omc stock ones are only $35. Thought they were more so that's good.