1975 75 hp Stinger no spark

[Bosunsmate]

Re: 1975 75 hp Stinger no spark

Three white black wires will be the timer base wires so test them too, their voltage will be low your book should tell you what value they should be, there resistance will be about 10-20 if OEM ones.
Stator will be the brown ones.
Yep coil wires out of powerpack will be orange and yes to ground.

 

[Bosunsmate]

Re: 1975 75 hp Stinger no spark

Timerbase tells each cylinder when to fire, thats why there is three sets of wire for them, one for each cylinder.
If timerbase aint working the powerppack wont be told when to fire and so it wont fire

 

[edquade]

Re: 1975 75 hp Stinger no spark

I checked the peak voltage, the stator wires are both giving me 1 volt, and the coil wires coming out of the powerpack are 0 volts. This information combined with the good resistance readings on the charge coil/stator wires and sensor wires should mean that its just the powerpack correct?

 

[Bosunsmate]

Re: 1975 75 hp Stinger no spark

I just looked up your engine, Try reading between the two brown wires.
You should get at least 150v


Then read White black to ground while cranking that should come in at least 150v too
If you get both of those replace powerpack
Remember its peak AC voltage so you need to measure it right.
Read page 3 of the link
ISSUU - CDI Electronics Practical Outboard Ignition Troubleshooting by CDI Electronics

 

[Bosunsmate]

Re: 1975 75 hp Stinger no spark

Powerpack looks to be about $90, so if your happy you have tested it as far as you can and resistance is fine then theres the decision and price to weigh up.

 

[edquade]

Re: 1975 75 hp Stinger no spark

Well, I bought a new powerpack, hooked it all up, had spark on all three just like a should. Came back an hour later to test fire it on the garden hose and no spark again.

 

[Bosunsmate]

Re: 1975 75 hp Stinger no spark

Nasty
try undoing the killwire again.
Check that killwire has no voltage reading on it,

 

[Bosunsmate]

Re: 1975 75 hp Stinger no spark

Had you put your replacement rectifier on before you fired it up?

 

[edquade]

Re: 1975 75 hp Stinger no spark

Well, I bought a new powerpack and installed it, seemed to work and I had a strong spark on all three cylinders. Came back about an hour later to fire it up on the garden hose, and had zero spark.

 

[Bosunsmate]

Re: 1975 75 hp Stinger no spark

To clarify my powerpack wire colors are starting on the left side going down.
Ignition coil 1 orange
Ignition coil 2 orange
Ignition coil 3 orange
Charge coil brown
Charge coil brown/yellow
Ignition switch black/yellow

Right side top going down:

vacant
sensor 1 white/black
sensor 2 white/black
sensor 3 white/black
sensor common black/white
ground lead black

The only wires I got a higher ohm reading was between the two charge coil wires, brown to brown/orange and that read 800 ohms.

So you didnt get any reading sensor wires to ground? as thats the only thing i can think of that will blow a powerpack repeatedly

 

[edquade]

Re: 1975 75 hp Stinger no spark

Just checked them again now, and I'm not getting any voltage from sensor wires to ground. Does that mean bad timing base?

 

[Bosunsmate]

Re: 1975 75 hp Stinger no spark

Just checked them again now, and I'm not getting any voltage from sensor wires to ground. Does that mean bad timing base?

Measure resistance to base, you are checking for a short in the timing base to ground ie you dont want it to read any ohmns to ground.
i have an away job to go too so make sure you run all those resistance tests again, maybe sneak the cdi back if possible too

 

[edquade]

Re: 1975 75 hp Stinger no spark

Alright. Just for giggles today I tried it. Good spark on all 3. This is beyond me.

 

[Bosunsmate]

Re: 1975 75 hp Stinger no spark

Yep i hear ya, intermittent faults seem to be the most devious.
You could try checking all wires thoroughly for bare patches for possible shorting to ground, plus squeezing them between your fingers to check integrity.
Eventually outboard wires perish internally and get broken but will often then somehow decide for themselves a few hours later that they now have enough continuity to transmit current along. You can normally feel a change in the wire through the insulation in such patches. Seems to happen most often near where the stator and timer base wires get grouped together to go under the flywheel

 

[edquade]

Re: 1975 75 hp Stinger no spark

Well, I tried it about 5 different times today and it sparked fine every time. Ended up taking her out to the lake tonight and she ran like a top, never missed a beat. Hopefully it stays that way!

Thank you so much for the help! I'm learning quite a bit from fine people like yourself!