74 Johnson V4 115hp no/weak spark. Help

[michigamiman]

I have a Johnson v4 115 hp that has lost power and now has no/weak spark. One day, while on plane & cruising along there was a cough & sputter then died out. Got it restarted, and barely got it to fire back up to get to the dock as it wanted to die with any acceleration. I bought new cdi coils(all 4) and swapped out for an extra used powerpack I had. All seemed well. Every so often it would seem to loose power, or not want to accelerate up onto plane. This season's first out it barely was able to get on plane due to the loss of power, but after a couple of laps on the lake it seemed to come back to full life. The next fees times I tried to get out the power was gone. Was barely able to get on plane. After removing, and cleaning carbs, and making sure I didn't have a fuel delivery issue (which I am very familiar with in these older motors). Next, I tested the spark with a gap tester, and found the issue -#1 weak spark #2 good spark #3&4 had no spark. So, in my ignorance I ordered a new power pack (cdi brand). I put it on and went for a test drive. It fired up great, and seemed at idle to be like new again. I let it warm up for a few minutes, then went into a normal acceleration onto plane. It was a huge improvement and felt as if all cylinders were firing, but it was not back to full power. Half way round the lake, it coughed and died. It barely fired back up, and barely ran well enough to put to the launch. After getting to the garage I see that the rectifier wired wrong(the red and yellow wires were reversed). The plastic insides were melted down the block. Now I just got this engine last summer and ran it wired like this since cuz I never looked at or changed any of the wiring, and it ran great when I got it. I took a rectifier off another motor that ran great till I stole it's power pack, and put it on. I went for a test run. It fired and idled way better then when I gimped it in last trip, but had no power, and would only mush hard, and not get on plane. I am afraid I tried my new power pack due to the backwards wiring of the rectifier. I am getting to swap the stator, and timing plate from the other motor that ran great til I robbed the power pack to get this one going... So, am I on the right track, and did I try my new power pack??? PLEASE HELP!! THANK YOU...

 

[interalian]

It's possible the miswired rectifier has damaged the stator. I'd check that first.

 

[michigamiman]

So, I switched out the stator, bought new spark plugs, cleaned all grounds & even added some extra grounds. Went for test run.. fired and ran but just like last time had no power. Ran just like it did after I replaced/rewired the rectifier, but before switching the stator. Thing is though, twice while idling it can to full life, but then right back to no power. So, I tested for spark at the launch by unhooking each spark plug wire one at a time to see what would change. #1 & #3 were sparking and #2 & #4 were not sparking at all. So, am I right to think I need to order a new 2nd power pack, I also switched the base timing plate when I changed the stator. Both parts came from the same motor that ran good till it had other parts robbed from it. Is there anything other then the timing base and power pack that would cause one side to fire, but not the other? Could the stator cause one side to fire but not the other?? Thanks for your help

 

[jbuote]

No expert here, but sounds to me like some testing with a multimeter and DVA adapter would be in order..
​CDI Electronics has a great troubleshooting guide on their website..
http://www.cdielectronics.com/troubleshootingguide/

My thoughts would be to test things out first, then replace only what you need to based on those results..

For what it's worth..

 

[michigamiman]

You sound much wiser then I... and that's why I''m here.. thanks you for the link.. I'll get the tester, and get to work... I don't have a DVA adaptor, or even know what it is, or where to get one..

 

[jbuote]

DVA adapter is a tool that plugs into a multimeter.. It allows measurement of peak voltage.
​99% of off the shelf multimeters can't read peak voltage, so the adapter was created. It plugs in where the test probes would on the multimeter..

​It's available in MANY places if you look.
​For example. It's available here at iBoats too:
http://www.iboats.com/DVA-Peak-Volta...SABEgLI2vD_BwE

(Edit: ​That said, you could do the tests that don't require the DVA adapter first.. But if you want a thorough test... Use a DVA adapter..)

​Wiser than you? Not so sure about that.. I'm a newbie myself to all this.. LOL..

The pro's here are top notch though!!

​Hope it helps!

 

[jakedaawg]

A compression test needs to be preformed before any further time or dollars spent.

 

[jbuote]

^^^^^^^ Listen to him(Pro!!) !!! (My newbie brain assumed since you were working on spark, compression was good. Should not have assumed anything.. My Bad.. :facepalm:​)

 

[michigamiman]

I am listening for sure that's why I'm here. To learn. So, I've got an update that I believe rules out low compression. I checked the ohm's on the stator-good/ base timing-good/coil packs-good. I don't have a DVA adaptor yet so I could not check that. So, I went to the water for some test. At first I had spark in one bank but not the other. So, I switched coils from one side to the other, and the spark followed the coils, as well as the misses. So, I grabbed the old coils I took off when I bought new last year to swap the 2 dead cylinders. The Johnson fired up nice, and ran smooth as silk. I had more power then I remembered ever having. It really came to life for bout two laps of the lake. Went home to trouble shoot some more. The old coils had 0 ohm reading in either the primary or secondary and we're cracked bad so I figured they burnt up due to age & deterioration.. So, I check all four new coils from last year to have all four read good at bout 300 ohms. So I'm racking my brain to figure why 2 coils that ohm good won't fire when it's was obvious the stator, base timing, and power pack were working all 4 cylinders. So, I remember having an issue with the spark plug wires that came with the new coils, and replacing them with automotive spark plug wires. Which I now think is my issue. I checked the ohm's on all four and the read around 3k ohm's. So, my theory at this point is that the automotive wires simply could not take the marine application and that the first two dead cylinders were the first 2 wires to fail, and the other two wires failed while running WOT when the ol' Johnson came to life for two laps In reading another thread on this site about outboard spark plug wires someone stated that outboard marine spark plug wires were stainless steel cores and should have no resistance. So I believe that the spark and no spark followed the plug wires not the coils as all 4 read good on ohms, until the last 2 wires failed in my two lap glory run. As far as compression I was told it tested about 130 to 135 on all cylinders last year when I bought the motor. I never checked it myself because it ran so good when I first got it. So, the only info about outboard spark plug wires I could find on the internet was found in the one statement in the tread stating that our outboard wires are stainless steel (while I know the automotive wires are not). So seems to me I need to order a new set of plug wires that are marine grade... Is my logic sounding, well logical, or like the hack novice I really am?? Also, my 2 lap glory run was with the old power pack I had replaced with new in attempt to trouble shoot my issues which indicates to me that my power pack never failed, and so now I have an extra new one. Does that sound right? Also for compression, my assumption is that it doesn't come and go but rather wears out over time and use unless something breaks, at which point it won't return without opening/rebuilding/fixing. Please tell if my assumption on compression are right or wrong as I am the ignorant one here in this discussion. Thank You to everyone for your input, and quick replies.. I hope to learn enough to help someone else one day as well.. THANK YOU!!

 

[jbuote]

Wow.. Yeah.. that's a lot of detail in there.. Kind of hard to read as there's no paragraphs, but I'll try...

​Old cracked coils should behave worse than new ones, so yes.. I'd lean towards the plug wires.. Automotive plug wires I don't think would work very well at all. (hence your issue).
​Probably on the right track there..
​Sounds like you probably now have a "spare" power pack too..

​Compression issues usually don't fix themselves.. Sometimes doing a de-carb can clean up sticking rings and compression comes back up, but usually not all by itself.. If it's otherwise running well, then compression probably isn't the "Big" issue..
​I'd still check it sooner rather than later since you haven't done that yet yourself, but no.. I wouldn't think it's that bad based on what I read...
(Edit: I JUST don't want to see you spend more money and time on an engine with deeper underlying expensive issues... A compression test will tell you the base health of the engine.. Again it doesn't sound like it's too bad, but without the test, it's all guesses...)

However..
​I am still really new, and I'm thinking this is probably about as far as I could be even a little helpful.
​I'm going to bow out of this now, and leave it to the more experienced folks to guide you from here...
​I'm subscribed though and would love to follow along and see how you make out!

​Might be able to help on some of the smaller/simpler things, but with detailed diagnostic (down to the ohm etc..) I leave it to the others here..
​Don't want to give incorrect or improper advice...

 

[michigamiman]

Sorry for the lack of paragraphs.. I was alway math orientated, and lacked in grammar. I will put forth better effort on that in future posts.

 

[jakedaawg]

Marine plug wires are different, I dont know if thats the issue. When you get your new ones post so someone can explain how to install the caps correctly. Basically you cut back 1/4' of insulation. The exposed wire then gets trapped in the winding of the spring with the shoulder of insulation right next to the spring, then you manipulate so that the sharp point of the spring pierces the insulation and goes through the insulated wire core, then dielectric grease is placed in the cap and lubricates it enough to slide the cap on. Cap=boot. whatever you want to call it.

You need to make absolutely sure that the cowl latches are not grounding out the bottom two plugs. Very common. There are insulated wire holders that route the plug wires so this does not happen, they MUST be used.

You can determine if this is the issue by running with the hood off.

A compression test should be done and noted, for future reference if nothing else. ALL out board trouble shooting on these motors requires a compression and spark test 1st. Every time. Its simple and only takes ten minutes. It's the 1st step of any competent marine tech.

If you go back and edit your posts to make them readable maybe you will get racerone or Joe Reeves or any of the guys who are really good and familiar with these old ones. I do not see them any more and am not as familiar with any of the little quirks or model differences that might pertain to them. What I laid out for you is basic info common to most v-4's. Many folks here have fporgotten more than I ever knew.

 

[michigamiman]

SOLVED!!!! I wanted to share so anyone else can maybe learn from my mistake. ALSO TO THANK EVERYONE FOR THEIR HELP!!!!

So, I got marine spark plug wire, and the Ol' Johnson ran the same. Two cylinders with spark, and two without. The miss followed the coil when they were switched cylinders.

So pulling out my hair, kicking the dog, and yelling at the wife... Just kidding cept for the pulling out of the hair. I took the nonworking coils to be tested at a small engine repair shop. I also took 4 older coils I had that looked really good with no cracking in them.

The lady at the shop asked if I was runing the newer nonfunctioning coil on the same motor as the old coils?? When I said yes, she told me that they were the WRONG coil packs for my motor. Thank God, all 4 of the older coils sparked a bright blue spark, and the sound of them snapped.

After getting home and installing the OLD coil packs my spark tester cracked a strong blue spark. In my excitement I headed for the lake were the Ol' girl fired like a champ. Smooth idle, took off like a rocket, and even increased my top speed. Oh, it was beautiful!!

After a few glory laps to make sure none of the coils petered out after getting warmed up, We grabbed the fishing poles, and caught dinner....

Thank you to all who gave me help. You never would have know sight unseen I had the wrong coils, but it was your guidance that got me through most every step that got me to the solution. From reading many threads on this site, and my own experience here I see a group of people wanting to help others, and not to be mushy but it's a beautifull thing. I hope even as a novice to pay it forward... THANK YOU ALL!!!

When I get few free minutes I'll edit my post into paragraphs so it will be easier for others to follow along.