formariz 11,987 #1 Posted November 11, 2022 (edited) My Electro 12 lost spark suddenly. I shut it off and could not start it again. I am pretty familiar with this system but it has me stumped. 1- coil tests good using all recommended tests. 2- trigger tests good. 3- switch kill wire is ok . Disconnected it to remove switch off equation. 4- With wire from trigger removed from coil when cranking I have 14 volts +/-. That also substantiates that trigger is ok? 5- plugging trigger wire back into coil and cranking, now I only have about 2 volts. 6- spark plug wire is also good. What is the problem? Any help is greatly appreciated. Edited November 11, 2022 by formariz 1 Share this post Link to post Share on other sites
Pullstart 62,905 #2 Posted November 11, 2022 looking forward to learning here… 1 Share this post Link to post Share on other sites
squonk 41,138 #3 Posted November 11, 2022 (edited) Inside the Trigger there is a "switch" When the switch is open, power flows to the coil primary, This is your 14 volts. When it closes, it creates a path for the 14 volts to ground inside the trigger. This stops the flow to the coil and collapses the primary circuit which induces the secondary high voltage spark. I think the switch in the trigger is faulty stuck closed. Removing the wire at the coil and checking voltage with a meter would give an easy path to ground. Voltage from the stator would flow from diode 2 to your meter. When that wire is connected to the coil it has to fight thru the coil primary resistance to ground so it flows thru the closed switch. Crank the engine and with a test light or analog meter, see if the light flashes or the meter pulses when cranking on the wire from the trigger at the coil.. Edited November 11, 2022 by squonk 2 1 Share this post Link to post Share on other sites
formariz 11,987 #4 Posted November 11, 2022 I don’t have an analogue meter. Please explain to me how to use the test light. Share this post Link to post Share on other sites
953 nut 55,286 #5 Posted November 11, 2022 A couple years back @Aldon had a thread going about the breaker-less ignition system. Lots of good information in it. 1 1 Share this post Link to post Share on other sites
squonk 41,138 #6 Posted November 11, 2022 Connect everything. Ground your test light. Place the probe of the light onto the coil terminal that comes from trigger. Crank the engine over. The light should blink. 1 Share this post Link to post Share on other sites
squonk 41,138 #7 Posted November 11, 2022 Section 8 of this PDF TP-2379.pdf Share this post Link to post Share on other sites
formariz 11,987 #8 Posted November 11, 2022 Thank you. Going out there in a minute. Share this post Link to post Share on other sites
squonk 41,138 #9 Posted November 11, 2022 I had a Raider 12 that ran funky. I discovered the spark was intermittently going out. I figured the trigger was starting to go. 50 yr. old electronics subject to extreme temps and vibration. Sold it to a guy who was going to convert it to points. Share this post Link to post Share on other sites
formariz 11,987 #10 Posted November 11, 2022 32 minutes ago, squonk said: Connect everything. Ground your test light. Place the probe of the light onto the coil terminal that comes from trigger. Crank the engine over. The light should blink. Light does not go on or blink! Share this post Link to post Share on other sites
squonk 41,138 #11 Posted November 11, 2022 Sounds like the switch is stuck closed in the trigger to me. The only other thing I could think of is something with the flywheel magnets not triggering the trigger Share this post Link to post Share on other sites
formariz 11,987 #12 Posted November 11, 2022 Forgive my ignorance here but this thing is obviously not related to wood unfortunately. Why do I measure voltage with a digital multi meter when cranking, but the test light will not go on? There is obviously voltage in there. 1 Share this post Link to post Share on other sites
Pullstart 62,905 #13 Posted November 11, 2022 Just now, formariz said: Forgive my ignorance here but this thing is obviously not related to wood unfortunately. Why do I measure voltage with a digital multi meter when cranking, but the test light will not go on? There is obviously voltage in there. There may not be enough true power (amps) getting through the switch, though the meter can see something. 2 Share this post Link to post Share on other sites
squonk 41,138 #14 Posted November 11, 2022 1 minute ago, formariz said: Forgive my ignorance here but this thing is obviously not related to wood unfortunately. Why do I measure voltage with a digital multi meter when cranking, but the test light will not go on? There is obviously voltage in there. 12 Volt test light is a 9 volt bulb with resistance. You measured 2 volts earlier and that would hardly light the bulb. Plus the resitsance would drag the little bit of voltage down further .A digital meter has a tiny resistance and can read voltage down to the tenths 3 Share this post Link to post Share on other sites
formariz 11,987 #15 Posted November 11, 2022 (edited) As much as I would like to leave this system in there, however, due to availability and price of parts, I don't believe it makes sense any more. With a battery ignition system anything is easily diagnosed and replaced quickly at a minimum cost. This is the plow tractor here and had this happened during snow, it would have been a very serious set back for me. I am going to change it. A bit of work considering that I also have to change switch and introduce a solenoid but I will have peace of mind with that system. This happened once before and it was the stator that was burnt when two wires at the rectifier loosened and shorted themselves.Tractor was down for over two months then until I found a stator. Edited November 11, 2022 by formariz 4 Share this post Link to post Share on other sites
ebinmaine 67,565 #16 Posted November 11, 2022 Excellent information here. Thanks for posting this stuff folks. Share this post Link to post Share on other sites
RJ Hamner 1,007 #17 Posted November 11, 2022 If you think these two parts will help solve your problem I'll send them to you I'll need an address Bob 5 Share this post Link to post Share on other sites
formariz 11,987 #18 Posted November 11, 2022 2 hours ago, RJ Hamner said: If you think these two parts will help solve your problem I'll send them to you I'll need an address Bob Thank you Bob. I wouldn’t mind trying the trigger which may be the culprit. I have a good coil Paul @oldredrider sent me. If it’s not trigger then perhaps it would be stator which I then will just convert it since I have all of those parts. I will PM you. 1 1 Share this post Link to post Share on other sites