No spark. '73 85 HP Chrysler

[idaho alan]

1st time here, sorry if this is too long...
I have a 1973 85 HP Chrysler outboard (model # 857HE, Ser # 8377). This motor has performed flawlessly until now. First the starter quit, I replaced that, now I don?t have any spark! I have probed through the wiring and found the following:

Key off: At terminal block; Red hot, Blue cold, White cold. All this seems as it should be.

Key on (run position): At terminal block; Red hot (12.4 V), Blue hot (12.3 V), White cold
At CD Unit, Coil and Dist:
Red hot (CD power in)
Blue hot (CD Ignition in)
Gray (coil +) cold 0.0 V
Black (coil -) cold, 0.0 V
White/Black (Dist +) 12.3 V with multimeter and buzzes with probe (typical ground one side, light bulb, hot other side which is a sharp point). I suspect the buzzing noise is adequate voltage with very low amperage (current) inadequate to light the light.

Key on, start position, starter cranking, Coil + (gray wire) still no light with electric probe. I believe I should have voltage going to the coil.

When I turn the key off, the Distributor wire (white/black) shows about 1.3 V and is dropping steadily (by hundredths of a volt). The Ignition terminal (blue wire) at the terminal block also shows dropping voltage (less than 1 V, dropping steadily). This could be a condenser draining?

Any suggestions?

I believe I have points ignition since I don?t have any other wires going to the distributor (ie: no blue wire). CD unit is all black, info on back is Motorola model # 6CB2012B, Ser # 88933 and a sticker with 185002.

Help, pleeease. Daughter standing here with the tow rope in her hand...

 

[Frank Acampora]

Re: No spark. '73 85 HP Chrysler

Your '73 will be CD ignition with points inside the distributor to signal the transistor in the CD box to dump capacitor power (capacitors within the box)into the coil.

The CD box has a red wire 12 volts pos. and a blue wire which should have 12 volts pos from the "I" terminal of the ignition switch at all times when the switch is on or in start position. If it does not, the switch is bad and no power is going to the CD box for spark.

The red wire powers the internal electronics, and the blue wire charges the internal capacitors and, I believe, powers the points.

I forget which it is, but for the sake of argument, lets say that when the points close, the switching transistor senses the current flow, closes the switch and dumps capacitor power into the coils

Therefore on the coils, black is the ground side and grey is hot but neither will show voltage until the points close. Therefore, if the points are mis-gapped, dirty, pitted, or greasy, the switching transistor will not dump power into the coil.

Nor sure if I read correctly: If you are getting a buzzing sound from the CD box, then it is bad and you need to replace it. If so, Go over to The Chrysler Crew

 

[idaho alan]

Re: No spark. '73 85 HP Chrysler

Frank, Thank you, I'll dig into the points tomorrow morning. I appreciate the help.

 

[idaho alan]

Re: No spark. '73 85 HP Chrysler

Frank, it was the points. After cleaning and regapping (twice) and working to get the timing right a few times it sputtered to life. We were out on the water today, and the motor ran great! Thank you for your help, a great day on the water makes time spent working on the boat worthwhile.