Sure ccould use some expert help on this ignition issue

[fleetwin]

I’m worried about your wiring, looks like the mag plate is broken where the leads would normally pass through to the underside of the mag plate. I don’t see any obvious areas where the wiring is rubbed through, but the flywheel is bound to rub sooner or later.
OK, you tried a different powerpack and got the same result.
Again, I’m wondering how you set the air gap on the charge coil and sensor coil…There is a ring that is used to set the air gap properly, trying to set the sensor air gap without the ring is nearly impossible. And, you don’t want to take a chance on the flywheel hitting your new components and ruining them.
While a weak flywheel magnet is always a possibility, it is rarely an issue on these engines. The "weaker" magnet might not be able to fire the sensor because the sensor is set too far away from the magnets. The only other issue that I can think of is a chafed/grounded lead on one of your new components. I would check for shorts to ground/mag plate, then check the resistance of the two components…
The only real way to check your weak magnet theory is to try another flywheel…
I would definitely replace the mag plate and use the original wire sheathing. Proper placement of mag plate wiring is extremely important, and will cause problems down the road….

[flyingvranch]

Thanks all for the advice. I have ordered a different flywheel and mag plate. Hopefully that will solve this problem. Meanwhile, I have tried a completely different set of components – charge coil, and sensor, and still have the same issue. The orange/blue wire coming from two different power packs is still dead. The only common denominator between the two sets are the mag plate and flywheel.

[frankr]

May I ask how you are testing for voltage on the orange/blue wire?

[flyingvranch]

I have all of the wires temporarily cut at the moment. When I hook the orange wire to an ignition coil I get hot spark. When I hook the same coil to the orange/blue wire I get nothing. That’s my unscientific way of doing it but it works OK for testing purposes.

[frankr]

Way back almost in another life, we had to go to school to learn electronic ignition systems. One thing that has stuck with me through the years was the command to never crank the motor over with any wires disconnected, unless specifically instructed to do so. To do it risks instantly destroying some expensive components. Many of learned the hard truth of that the first time we yanked the rope on an Eska with the plug out.

Anyhoo, I’m wondering what would happen if you crank a motor like yours with the coils disconnected? Needless to say, I don’t know because I learned my lesson well and never tried it.

Anybody?

[flyingvranch]

I fiddled with adjusting the gap on the charge coil and the sensor a bit. I actually had an intermittent spark on the dead side momentarily. I’m pretty sure it’s the flywheel magnet being weak. I’ll find out in a few days when I get another one.

[garry-in-michigan]

They don’t guarantee those electronics because they are very sensitive to voltage spikes or reversed polarity. I learned the battery in my old analog volt meter was enough the destroy the black box just by checking the voltage. The safe digital replacement was 4 times as expensive. Always be sure both you and the workbench are grounded before touching anything. . . 😕

[flyingvranch]

I’ll wrap this up and tell you that it turned out to be a bad sensor unit. On another forum a fellow told me to reverse the wires coming from the sensor and I tried that and got spark to the non-working coil. That told me it was the trigger, so I replaced it and now I have a hot spark on both coils. Many thanks to all that helped me and gave some good troubleshooting advice. Thank You!

[billw]

I have to admit that I didn’t know that was possible and I don’t understand why. Isn’t the sensor coil just that, a coil? I can see where reversing the wires would reverse the firing sequence but beyond that, I don’t get it. Anyway, thanks for sharing the results with us. I am going to learn something here.

Long live American manufacturing!

[fleetwin]

Would love to have the bad sensor to check it out…But, like Bill says, hard to imagine how the sensor could fail this way. Perhaps one of the leads was shorted to the mag plate slightly…
Nonetheless, one thing I have tried to learn over the years is "never argue with success"….

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