Coils randomly burning out

[Carl77]

Here is what I’m dealing with, I have a carbureted 1997 Evinrude 225 Vindicator. I purchased the boat about four months ago, the more I ran it the worse it seemed to get. First I thought carburetors so I rebuilt them, then I went back through spark test and found number 2 cylinder coil dead. So I replaced it with a new OEM coil, took the boat out ran better at first then back to shit. Brought boat back to house put on the muffs and went through the process of spark check with 7/16 gap tester. I then found number 6 cylinder would fire then not fire. I then switched leads with another cylinder and the same problem followed the coil switch. So I took it to shop because I know something wasn’t right, two weeks later the so called mechanic who had been working on boats since he was 13 said “ you have a bad coil on number 6”, no shit!! I told him something else was wrong, he said “nope the problem is fixed, she runs like a beast now”. When I picked up the boat he put it on muffs and started her, “see your good to go”. I did have him pull the flywheel when it was there to see if the black sticky substance on the base of CDI was new or old, he said “Stator looks great, black stick must be old”. So, I took boat to lake and sure enough not fixed. I got her back to the house where I found number 3 coil spark then not spark, switched leads again and problem moved with same coil different cylinder. I then ran to the local boat store and got a new OEM coil, put it on coil fires great, but then the new coil on number 6 goes out, fires then doesn’t fire. There went that new coil. What keeps frying my coils, Stator, regulator? Sorry for the long posts but wanted to explain the best I could what is going on. Oh, I forgot to mention that my tach is now acting up, it’s not bouncing but it steadily rises to high rpm without the engine running at a high rpm. Also I forgot to mention that the voltage going back into battery at idle is 14.6
Thanks in advance

[SEAHORSE]

Are you using NGK plugs or have automotive plug wires installed ?

Pull your flywheel to check the magnets for cracks or looseness, who knows if that mechanic checked them.

Wing nuts on the battery cables? A faulty regulator can sometimes affect ignition if the situation is just right, but its rare but not unheard of.

[Carl77]

Thanks for replying Seahorse, I am running new Champion plugs that I bought from MarineEngine.com for what my motor called for. As far as plug wires, I have not changed them but they look like they are Marine wires. I don’t think I have wing nuts but I will check.
Thanks again

[Carl77]

I was wrong, I do have wing nuts on cranking battery. They are tightened with a wrench, what’s the issue with wing nuts?
Anyway I will change to regular nuts tomorrow.

[ChampioNman]

If you read the post I made on the Champion boats forum in reply to your question you'll see that I said to check for wing nuts on the battery. I said to remove them and replace them with SS star washers and SS hex nuts. A loose motor ground can also cause this issue.

[Carl77]

Yes, I believe I responded to you over on the Champion boat forum. I am going to rid of those wing nuts today even though they are tight as hell. In response to Seahorse and you, is the issue with wing nuts is the loosen up on their own?

Much appreciate the advice.

[Carl77]

Ok, wing nuts even though extremely tight are now replaced with hex. I also checked the ground on starter, tight.

[Carl77]

What is the best way to check the regulator?

[ChampioNman]

First thing I would do is ohm out each coil ground to the main engine ground and check for continuity. To check the charge part, connect the meter set on DC volts to the cranking battery, before starting the motor get a voltage reading and then start the motor and observe the reading. It should not exceed 14.2 VDC. To check the tach connect the meter leads to the rear of the tach. Purple will be battery voltage when measured to ground on the back of the meter. The I post will be your tach signal and measured a AC voltage should be around 6-9 VAC with the motor running. If your VRO harness is still connected disconnect it temporarily and see if full tach function returns.

[Carl77]

Thank you ChampionMan. Could you explain to me the process/ how to on the coil ground ohm test. Also I just did a thorough visual on my Stator from underneath. I found on almost every coil on my Stator, harden drip from melting. I have pics but they are to big in size to upload and I don’t know how to shrink them.
Would a bad Stator cause the problems I am having?
I also previously did the volt test on battery at idle, it was 14.7 or so.

[ChampioNman]

Sure set your volt meter to ohms, connect one lead to the main engine ground, and the other lead to the coil bolt that has the metal strip on it that is the ground for the coil, it should show a dead short. A bad stator would/could be the cause if it is putting out too much voltage as there are two leads from the stator to the power pack, the leads from the pack go to the coils.

[Carl77]

All coils show good on the ground ohm test. Now to figure out how to test Stator, also to check rectifier while I’m at it. I’m trying find what ohm ranger the Stator and rectifier should be in. You’ve been very helpful ChampionMan, thank you. I welcome your advice.

[ChampioNman]

Carl if you don't have a service manual here is a link for a factory service manual you can download for ~$15.00 it is in PDF format so it makes it convenient for you. https://www.selffixer.com/outboard.m...ual.507269.htm the ignition system tests will be in chapter 3.

[Carl77]

ChampionMAN, you are full of all kinds of good info. A few weeks ago i bought the Seloconline manual, I'm not really liking it all that much though. I previewed the selffixer manual and it seems more user friendly, or at least it works with my mind better then the Seloc one does. I'm hopping I can get to the bottom of this soon so I can see how " MY Girl " 1998 202 DC really preforms.

Thanks again for your time and knowledge.

[txfour]

The selfixer manual is a good one.

Have you checked your plug wires and plugs? A plug wire can have intermittent firing.

Video for plug wire test. Make sure you bend and flex the wire while doing the test.


Video for plug test

[Carl77]

Thanks for the info and taking the time to post the videos on here for me. I did awhile back check the wires, but cant remember if i did all the wires or only the one on the coil that was giving me the problem at the time.
Thanks again Texfour.

[Carl77]

Ok, got the time to pull the flywheel and got a good look at all the coils on the Stator. Hard melting drips on just about all the coils, so ether the boat repair shop I took it to didn''t pull the flywheel like he said he did or just does not know his stuff. Because he told be he pulled it and it looked knew, BULL SHIT!!!!!
So I did ohm test on the Stator and here is what I found-

Orange wires which I think are the Ignition coil is reading 142 ohms, the book is saying it should be between 225-325 ohms.
Brown wires starboard side read 952 ohms, Port side read 973 ohms, book says 765-935 ohms.
Yellow wires are reading 1.6 ohms, book says .11-.21 ohms.

So with seeing the hard melting drips and the black goo at the base and know with the reading from the meter, I'm guessing my Stator is Shot?
I take it that would cause my sporadic fire and randomly frying coils?

[Carl77]

Finally got to the bottom of my issue. I replaced the Stator with a new one, because of the visual signs and the meter reading but still had the same issue. After further testing I found that the Purple wire on both the port and starboard side coming off the timer base has no resistance. Hints why I was getting erratic spark at best on number 3 and 4 cylinder. Waiting on new timer base to arrive Wednesday.