Motor Won’t Shut Off…Again

[johnyrude200]

Well maybe it was a bad connector coming from the trigger then (the 3 wire lead, 2 browns and the black). All I know is I followed the adage ‘don’t argue with success!’ 😀

[billw]

Isn’t the stop wire in the same amphenol connector as the trigger wires, on those engines? Right up near the top of the head? Possibly just the disturbed the plug while changing the trigger and made the stop connection work again?

Long live American manufacturing!

[jerry-ahrens]

Bill I think you got it right on the connector. My 81 25 has that arrangement. It seems to me, that pushing the anphenol connectors together dry, can cause the pins to back out [or break], resulting in an ”open” circuit. And you may not even notice it by looking at the connector. I must confess, I’ve been guilty of that myself.
Johnnyrude, I would suggest picking up a copy of ”CDI Electronics Ignition Systems Troubleshooting Guide”. probably the best, most detailed guide I have found. The guide walks you through the testing procedures, and includes testing data. I refer to mine for engines I may be ”rusty” on, as far as wire colors and specs, etc. Do you have a DVA meter for testing? I’m sure you know this already, but a standard issue multi meter will not test DVA voltage. This, along with a ”Pack Load Resistor” for testing some OMC engines is also a requirement. Stevens Instruments in Waukegan Ill. still has the pack load resistors, as well as the DVA test equipment. I kind of like my Electro Specialties brand DVA meter [Mercury Marine tool] that I’ve used forever. It has a DVA function, as well as a standard multimeter all in one.

[Casey Lynn]

Didn’t T2Stroke send you a bunch of manuals?
A simple check of any one of those would have told you exactly what to look for and how to troubleshoot.

[fleetwin]

Well, I think that terminology might just be the cause of confusion here…."Trigger/switch box" is a term used by merc, whereas OMC always referred to them as the powerpack. When you say trigger, I am "asssssuming" you replaced the sensor coil or the complete potted stator (electric start models). Perhaps we are misunderstanding what part you replaced that solved the problem.
In any event, the 82 35hp with CDII has two harness leads coming off the powerpack (along with one ground lead). One of the harness leads has three terminals: the two coil leads (orange or perhaps brown looking) and the stop lead. The stop lead is black/yellow tracer, but sometimes the engine harness side might just be black. The other powerpack harness lead has four leads: two brown leads (one with yellow tracer that are charge coil leads (the term charge coil is confusing because it is often understandably confused with some sort of alternator function, but is an ignition part) and the two sensor leads (one black/one white).
Just because this is the way the 82 35hp rolled off the assembly line does not mean the ignition system has not been messed with/altered/cobbed up along the way. Someone could have used a later style powerpack and fudged the leads accordingly. Jeez, for all we know, someone could have changed this ignition to UFI, who knows!
So, I too don’t think the sensor could have caused this engine not to shut off properly. I’m thinking funky connections probably got repaired coincidentally when the sensor was replaced. BUT, I know enough about my lack of electronics knowledge to "never say never". Nonetheless, the important thing is it works properly now…..I too have learned never to question success….

[johnyrude200]

Well, typing posts is never as clear as looking at the same thing in person, so I appreciate the effort of folks to offer professional advice. I’ll be heading out in a few minutes to get back to work on this suspect motor and will report back.

[jeff-register]

Don,
If I may ask? Your charge coil is really a capacitor & silicon controlled rectifier for switching thresh hold voltage for the ign coil? Not trying to make a statement, but see if I understand the electronics correctly or am I all wet here? Please anyone & Thank you. Jeff, Seems to me all is needed is to ground the gate terminal of the scr. Correct? No?

[johnyrude200]

Well got the motor resolved yesterday. Simple issue; the big red plug black/yellow lead had failed. Repaired/replaced and all as well. Perhaps that was the same issue on the other motor I mentioned too…learn something new everyday!

Thank you all!

[fleetwin]

quote Jeff Register:

Don,
If I may ask? Your charge coil is really a capacitor & silicon controlled rectifier for switching thresh hold voltage for the ign coil? Not trying to make a statement, but see if I understand the electronics correctly or am I all wet here? Please anyone & Thank you. Jeff, Seems to me all is needed is to ground the gate terminal of the scr. Correct? No?

Jeff, the "charge coil" is just a simple single coil winding that develops about 150 volts AC when the flywheel magnets pass by. This voltage is sent to the powerpack, rectified, then stored in the powerpack’s capacitor. The sensor(s) tell the powerpack when and to what cylinder/coil to send this primary voltage stored in the capacitor.
The OMC term "charge coil" is understandably confused with 12 volt alternator function, but it has nothing to do with that system, there is a separate winding for the alternator (if equipped).
The SCRs that you refer to are located inside the powerpack and are controlled by the sensor(s) telling the powerpack when and what cylinder/coil to release the voltage stored in the powerpack’s capacitor.

[fleetwin]

quote johnyrude200:

Well got the motor resolved yesterday. Simple issue; the big red plug black/yellow lead had failed. Repaired/replaced and all as well. Perhaps that was the same issue on the other motor I mentioned too…learn something new everyday!

Thank you all!

Glad it is resolved! EVERYDAY is a school day for me, my best lessons usually have come from my worst screw ups!

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