75 HP Chrysler with no spark.

[kbh121956]

1979 Chrysler 75hp Model# 759H9A. Working on a friends outboard, no spark at all on all three plugs. It has one CD module, a small round ignition coil, a distributor, and no breaker points. Where do I start for checking bad components? All connections clean and good, battery is fully charged.

 

[kbh121956]

What I have done for testing. I removed the white/black wire from the distributer post. I also removed the coil high tension wire, from the coil I installed a spark tester to a ground in place of the high tension lead. I powered on the key switch, Touched the white/black wire to a good ground. Shouldn't this make the spark tester show a spark? It doesn't. I would assume that the magnapower box is bad. Anyway to test the electronic distributer?

 

[Tassie 1]

Have the same ignition system on a '79 yr 70 hp,
I'd look at either the CD module or the distributor being the villian here,

there are test procedures for the dizzy in the manual but not sure about the CD module,

it either works or it don't,

we replaced the original CD module with a aftermarket model after the original failed 5 months or so after buying the motor,

1st tow of shame in decades,
at least it was a week day AND the towie was my son

Decided to get the above aftermarket CD Module
worked well for 8-9 trips then backfired big time at the ramp prior to heading out,
cracked the shites and drove 400 mts home
NO spark but at least l didn't need a tow...then

after a few months l decided to give it a chance to redeem itself and bought a 2nd hand dizzy and coil
( we have other boats as well )

ran well for 8-9 trips and then it happened again...shat it self,

this time it was a summer weekend AND this time EVERYONE saw us being towed in by my sons employers workboat...

there was mucho mockery directed at us in town after that by mean, mean people

The 2nd tow of shame...towed in twice in 30 odd yrs and each time the same Chrysler motor was the culprit,

won't be a third time...

morale of the story?
40 yr old...or more or even less...Chrysler outboard motors are not a good reliable source of propulsion, even if you are just using it to get out to a moored fb cruiser in Tasmania,
cheers

 

[kbh121956]

Tassie 1, I've had good luck with the Force outboards. This one is a friends and I have no manual for it to go by. I'm trying to figure it out, I'm learning from it. The stator looks good! LOL.

 

[Tassie 1]

There is a troubleshooting guide on the CDI Electronics website or similiar name,

CD module or distributor will be the issue,
l'll bet my life savings on it....pretty safe there,

over the years we've had 10 or so Chryslers from 6hp to 120hp
slow learners...but not complete loons... had other brands as well

 

[Nordin]

If you have unhooked the white/black wire and scratch it to good ground with keyswitch in ON position and no spark, the issue is the CD module, keyswitch or igniton coil.

What you do when scratching is to simulate the points or the preamp (if electronic dist.) to open
When this the CD module should dump the charged voltage from the capacitors inside the box through the ignition coil.

Measure with a VOM at the white/black wire to good ground and with the keyswitch in ON position.
You should read about 12VDC, if not the keyswitch is bad or the harness from keyswitch.

Measure the ignition coil resistance, primary side should read 0,3-1,5 Ohm, secondary side 5-600 Ohm.

If all this checks out okey, then it is the CD module that is bad.

From my experience of this ignition system the ignition coil do not fail very offen, the keyswitch do not fail very offen.
Most of the time it is the CD module.

 

[jerryjerry05]

outboardignitiondotcom
Test procedures.

 

[kbh121956]

If you have unhooked the white/black wire and scratch it to good ground with keyswitch in ON position and no spark, the issue is the CD module, keyswitch or igniton coil.

What you do when scratching is to simulate the points or the preamp (if electronic dist.) to open
When this the CD module should dump the charged voltage from the capacitors inside the box through the ignition coil.

Measure with a VOM at the white/black wire to good ground and with the keyswitch in ON position.
You should read about 12VDC, if not the keyswitch is bad or the harness from keyswitch.

Measure the ignition coil resistance, primary side should read 0,3-1,5 Ohm, secondary side 5-600 Ohm.

If all this checks out okey, then it is the CD module that is bad.

From my experience of this ignition system the ignition coil do not fail very offen, the keyswitch do not fail very offen.
Most of the time it is the CD module.

Thanks Nordin and everyone else for the reply's. What I did was remove the red and blue wires from the terminal block and powered them up together + volts. This should remove the keyswitch from the circuit? I did swap out the coil to a good known coil. I'm thinking that the CD box is gone.

 

[Nordin]

kbh121956 you are on the right way, as you power the blue and red with 12VDC from another source you elimintate the keyswitch.
My gut feeling says it is the CD module that is bad.

I do not know if you know that you can convert the system to an automotive typ, but then you have to change the dist. to a points dist. if yours is an Electronic with a preamp.

 

[kbh121956]

kbh121956 you are on the right way, as you power the blue and red with 12VDC from another source you elimintate the keyswitch.
My gut feeling says it is the CD module that is bad.

I do not know if you know that you can convert the system to an automotive typ, but then you have to change the dist. to a points dist. if yours is an Electronic with a preamp.

Nordin, yes this is an electronic distributor. I removed the Magnapower from the engine. I grounded the box. I used a spark tester from the coil to ground. I taped off the white wire from the box so that it couldn't touch anything. I powered up both the blue and red wires, positive 12 volts. Each time that I touch the white/black wire to ground, I get a very nice spark on the spark tester. When it's all installed on the powerhead, I get nothing! Any ideas? Also thank you everyone.

 

[Nordin]

Okey then the CD box is working.

1. Check for 12VDC at blue and red wire at the terminal stripe at the engine to ground when keyswitch is in ON position.
If that checks out good then you know the keyswitch is okey.

2. Check the grounding of the CD box at the engine and especially the ground wire to the dist as the svivel in the dist has greas and will isolate the grounding.

If all this checks out good then it is the preamp in the dist that is bad. The preamp is an electronic eye (opto) that replaces the points.
When the voltage goes from 12VDC to 0V or the other way (I am not really sure which way) the CD box dump the voltage that is stored in the capacitors in the box.

 

[kbh121956]

Thank you Nordin. I will check this later on today and post results. I am a mechanic but, I am not a marine mechanic. I am learning with the help of you guys.

 

[kbh121956]

What an adventure! What I learned was how to check the Magnapower system's used on the old Chrysler outboards. I corrected the wiring at the ignition switch and she fired right up. Thanks for all the help. This post is finished.

 

[VivaLaMigra]

Tassie, that old Magnapower system was as "reliable" as anything else on the market at the time. I'll take it any day over the Rube Goldberg system that Force [US Marine] put on with two power packs on 3 -cylinder, leaving one circuit on one pack unused. If you have the early one with points in what you call the "dizzy" you can eliminate the Motorola capacitor pack in favor of an old-time ignition coil and conventional plugs like Champion J6C's. I'm told there may be a top-end power drop-off and even worse fuel economy than a cross-fire 2-stroke generally gets, but it will run like that and you can find a bunch of Y/T videos to prove it. Remember, that's exactly the system Chrysler used on their 45's and 55's only with two sets of points and two coils so they didn't need a "dizzy." I just sold a 45 like that and it fires up first turn even without the choke.