1989 Johnson TJ50TLCEC No Spark

[tr@v1s]

Hey all. Having problems testing for correct issue on this motor. I've looked up what I believe is the correct page in the CDI manual (screen shot included), but none of the wire colors seem to match up. I have also checked wire color verses pictures of original parts from parts manual and my wire colors do look correct.

I bought the boat recently. It didn't have spark at first, but wiggled a few things around and not only had spark, but started and ran for a 20 seconds or so (no water) and shut off. I bought it knowing it needed the impeller replaced. Fixed my tilt/trim unit and moved on to getting motor running well. Now I have no spark.

Here's where I am:

Tested with spark testers on both cylinders multiple times. No apark.

Coil pack is correct part #. Tests primary to ground less than 1 ohm. Primary to secondary about 300 ohms. This is the dual cylinder pack and readings are near identical on both sides.

Power pack calls for part# 584489 but I have part#583656. My wire colors are:
Orange/blue stripe
Orange/green stripe
Tan (brown?)
Black
Black/yellow stripe

Stator part number calls for 584341. I have not removed mine, but didn't see a part number anywhere on it. My wire colors are:
Yellow
Yellow/gray(white?) stripe
Yellow/blue stripe

Rectifier calls for part # 581778. Wire colors are:
Yellow
Red
Yellow/gray(white?) stripe
Yellow/blue spark.

If anyone can help on this, I woukd really appreciate it. I will add some pictures for reference.

 

[tr@v1s]

And yes, I have unhooked the black/yellow stripe (kill switch) wire unhooked.

 

[saltchuckmatt]

Sounds like it could be a bad wire...time to do some continuity testing.

Wire or stator is my guess.

 

[tr@v1s]

Sounds like it could be a bad wire...time to do some continuity testing.

Wire or stator is my guess.

Agree. But where do I find correct resistance readings for my specific unit. it seems what I found on CDI manual doesn't line up with my wire colors unless I am completely misunderstanding...

 

[saltchuckmatt]

You made this statement..." my wire colors do look correct " max rules has color charts but you already must know.

Continuity test on wires should come out with 0 resistance. Resistants for your stator coil will be listed online.

All the ignition systems can be tested but the power pack. If all else is good, then it's bad but you have 2 so less likely.

Flywheel key good? Flywheel magnets intact?

 

[racerone]

Test the charge coil.----Remove powerpack and look for bare wires.----Look into a conversion kit to move a new powerpack from under the flywheel.

 

[saltchuckmatt]

Got confused with another thread...you have one power pack so that could be your problem. Rule out the stator/charge coil/chaffed wires then pp is the issue assuming all connection have been gone through. (Corrosion)

Salt water motor?

 

[tr@v1s]

You made this statement..." my wire colors do look correct " max rules has color charts but you already must know.

I was saying they look correct when compared to pictures of OEM parts off marineengine.com parts manual. But they do not line up with the colors listed in the CDI manual that I posted a screenshot of.

Continuity test on wires should come out with 0 resistance. Resistants for your stator coil will be listed online.

If you mean online as far as the CDI manual, I've got that, but not the same wire colors I am seeing as I posted in pictures.

All the ignition systems can be tested but the power pack. If all else is good, then it's bad but you have 2 so less likely.

I thought CDI was indicating that power pack could be tested. The smaller power pack plugs into the bigger power pack with no wires leading elsewhere. Figured this out after pulling flywheel and removing all components to find the brown and brown/yellow under that smaller pack. was able to test those and came up with correct resistance (500-650 ohms) according to CDI manual. I cannot find the 'trigger' wires though. CDI calls for a black/white and white/black wire - but I do not see those anywhere coming from any component coming from under the flywheel.

Flywheel key good? Flywheel magnets intact?

Key/keyway looked good. Flywheel was definitely locked on solid. I'm definitely no expert, but I think everything looks good where the magnets are concerned. I didn't see any obvious damage.

After I put everything back together last night, I got one spark on one cylinder (have 2 spark testers hooked up to check both cylinders at the same time) the first time I cranked it over. Nothing after that.

 

[tr@v1s]

Test the charge coil.----Remove powerpack and look for bare wires.----Look into a conversion kit to move a new powerpack from under the flywheel.

Charge coil is the smaller coil with only two wires. Correct? If so, that tested out with correct ohms of 550 brown to brown/yellow.

I did see that Sierra makes a conversion kit, but didn't realize what it was for. Is that when the 'trigger' becomes a thing and why I am not seeing the trigger wires now with my pack being under the flywheel?

Sorry if I sound like an idiot guys. I work as an electrical controls engineer (not an electrical engineer by training or license - I wire, install, program, troubleshoot and sometimes design control systems on industrial equipment) but I am not familiar with ignition systems at all. So, while I'm more than used to dealing with meters, wires, and all that, I don't really understand how the ignition system works on this thing. Guess I need to watch a few videos on that.

 

[racerone]

The trigger is part of the powerpack.----Install the conversion kit and go fishing.

 

[tr@v1s]

Got confused with another thread...you have one power pack so that could be your problem. Rule out the stator/charge coil/chaffed wires then pp is the issue assuming all connection have been gone through. (Corrosion)

The only thing I have been able to rule out so far is the ignition coil tests as it should (though it does have some cracks and I'm replacing as a preventative measure since it's only $30 or so) and the rectifier is definitely bad as evidenced by a bad wire that was damaged almost all the way back to the rectifier itself. But, if what I've read online is correct, unhooking the rectifier should still allow the ignition system to function properly - is that correct?
How would I test the stator? Can't seem to find correct info based on my wire colors.

Salt water motor?

No sir.

 

[tr@v1s]

The trigger is part of the powerpack.----Install the conversion kit and go fishing.

Here is the Sierra conversion kit: https://www.marineengine.com/newparts/part_details.php?pnum=SIE18-99213

What is the benefit of the conversion kit verses just replacing the power pack?

I'm really wanting to learn more about diagnosing these things - partially because I enjoy learning, partially because I hate replacing parts that I haven't proven bad, and partially cause I'm just hard headed. How can I prove the power pack as bad with my meter before replacing?

 

[saltchuckmatt]

The only thing I have been able to rule out so far is the ignition coil tests as it should (though it does have some cracks and I'm replacing as a preventative measure since it's only $30 or so) and the rectifier is definitely bad as evidenced by a bad wire that was damaged almost all the way back to the rectifier itself. But, if what I've read online is correct, unhooking the rectifier should still allow the ignition system to function properly - is that correct?
How would I test the stator? Can't seem to find correct info based on my wire colors.

Rectifier converts ac to DC power to charge the battery...running it unhooked will fry it. It does not affect it's ability to run though.

You need a DVA adapter to test correctly but if everything checks out ohm wise replace the pack as directed.