1973 85 hp Johnson ourboard - Turns over great but will not start

[WDC]

Past

Bought 4 years ago and has been running fine. Takes a little while to start but once started is fine. Restarts in a snap easily after warmup.


Now

Not starting this year.

Troubleshooting

No spark to any of the plugs.
Ignition key wires intact
Battery well charged
Turns over easily

4 Coils - 2.07 kOHM on three of the cylinders
0.0 KOom on on cylinder

Note the coil that reads no ohms looks the same shape and size as the other three but its different in color. The other three look original and this one appears like it was changed a long time back, Not sure or could be the reverse.

If one coil goes does it affect the other coils? Should I replace the bad coil and retest?




No spark to plugs

 

[Daviet]

Re: 1973 85 hp Johnson ourboard - Turns over great but will not start

A bad coil should not affect the other coils. Look on your power pack and see if you have a black wire with a yellow tracer, disconnect it and see if you have spark. If you get spark you have a problem in the kill circut. The rest of your ign system is under the flywheel and will have to be tested. Do you have a factory manual for your engine, it will have all the specs and test procedures for your engine.

 

[WDC]

Re: 1973 85 hp Johnson ourboard - Turns over great but will not start

Thank You very much. I will do that.

 

[WDC]

Re: 1973 85 hp Johnson ourboard - Turns over great but will not start

Daviet,

Pulled off the flywheel and tested the stator. It should not be grounded or shorted. Per the manual pulled the yellow and yellow grey wire from the terminals. Each wire to ground there was resistance and with wires connected together there was resistance. There appears to be a short but there are four wires. Two yellow wires that go to the terminals and a brown/brown yellow that goes to the power pack. Am I measuring this right? Also how do I know what stator to buy.

 

[emdsapmgr]

Re: 1973 85 hp Johnson ourboard - Turns over great but will not start

CDI.com has some good ignition troubleshooting tips that you may find helpful.

 

[WDC]

Re: 1973 85 hp Johnson ourboard - Turns over great but will not start

Thanks. Thee are two measures the trigger and the stator(charge coil) I am currently checking. The stator creates ac voltage and without it there is no spark. The rectifier coverts it to dc.

Tested the ohms(stator charge coil) and was about 615 a little out of range 400-600 ohms CDI spec(brown to brown/yellow wire). I know the DVA voltage is a special test but my question is you must turn over the motor to do it correct?? You would not be able to create that voltage.

I measured the trigger and they are in spec 12 ohms spec is 10 -20 ohms. Have not measured the DVA yet. The trigger( #1 to #3 and #2 to #4) appear to be sensors for the stator four since four cylinders. Is that correct?