Mid 70’s OMC. No spark.

[elgin2]

[fleetwin]

OK, well the heavier yellow wires are for the alternator windings and have nothing to do with spark.  Those two black coil windings are what is referred to as the “charge coil”, which is a little confusing, nothing to do with charging the 12volt battery.  The charge coil is what produces the AC voltage that is stored in the powerpack.  So, on this engine there is only one charge coil lead, it is brown, the circuit back to the charge coil is completed through ground.    So, in order to check the charge coil, you must remove the brown lead from the powerpack and check it resistance to ground.  I don’t have the exact spec, will get it, but am guessing it is several hundred ohms.

The sensor coil is that inner ring that houses the small winding, two black/white wires.  To check the resistance of the sensor coil, you must remove the two black/white leads from the powerpack and check the resistance between them, should be about 40 ohms.  Check each sesnor lead for shorts to ground, should read infinity.   Be sure to get those sensor leads properly reinstalled or your timing will be 180 degrees off.

The first test I would perform is to remove the “stop lead” from the powerpack, which is a black lead with a yellow tracer.  Check for spark with the stop lead removed.  If spark is present now, then there is an issue with the key switch/wiring.  I would also check all ground connections, should read less than one ohm.

[jeff-register]

Thank you Fleetwin! I think a few of us got an education! Thank you! Onlyitem I knew was the alternator windings 😉 Wasn’t an older motor have a charge coil to run navigation lights or is my memory going away?

Jeff

[fleetwin]

jeff-register wrote:

Thank you Fleetwin! I think a few of us got an education! Thank you! Onlyitem I knew was the alternator windings 😉 Wasn’t an older motor have a charge coil to run navigation lights or is my memory going away?

Jeff

Well, it is the terminology that confuses us for sure.  The “stator” includes two separate electrical components.  The term “charge coil” is misleading.  The “charge coil” charged up the ignition power pack, while the heavier yellow leads/windings were for charging the 12 volt battery.  I always refer to this component as the “alternator windings”.

And your memory is spot on.  Some of the newer smaller engines sold outside the US had what was referred to as the “AC lighting coil” along with the usual charge coil.  This “AC lighting coil” was found on some smaller/midsize engines that were manual start.  Many countries required this feature to power running lights.  The “AC lighting coil” was very similar to the alternator windings, but did not use the usual rectifier.  The lighting coil provided AC voltage for running lights on manual start engines with no 12 volt battery.

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