testing magneto ignition
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testing magneto ignition
Quadra 75 with Magneto.
Been 6 years at least since I've fired it up. Rebuilt the carb.
Does not seem to ignite.
How can I safely test the ignition in my basement?
Pull plug and ground to case and spin the prop?
David
Been 6 years at least since I've fired it up. Rebuilt the carb.
Does not seem to ignite.
How can I safely test the ignition in my basement?
Pull plug and ground to case and spin the prop?
David
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RE: testing magneto ignition
Could not see a spark. Turned the lights down some too.
The black coil box has 2 wires that go to the engine case.
One directly to it, the other goes to it through the ignition switch.
Both test good continuity to the case.
Can that coil and spark plug wire be found at a local small machine shop or would I have to order one?
Also, I"m finging Allen head cap head screws that don't fit my allen tools.
It uses something between 1/8" and 5/32". Is that SAE or Metric? What size?
David
The black coil box has 2 wires that go to the engine case.
One directly to it, the other goes to it through the ignition switch.
Both test good continuity to the case.
Can that coil and spark plug wire be found at a local small machine shop or would I have to order one?
Also, I"m finging Allen head cap head screws that don't fit my allen tools.
It uses something between 1/8" and 5/32". Is that SAE or Metric? What size?
David
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RE: testing magneto ignition
ORIGINAL: dditch
Could not see a spark. Turned the lights down some too.
The black coil box has 2 wires that go to the engine case.
One directly to it, the other goes to it through the ignition switch.
Both test good continuity to the case.
Could not see a spark. Turned the lights down some too.
The black coil box has 2 wires that go to the engine case.
One directly to it, the other goes to it through the ignition switch.
Both test good continuity to the case.
CR
#6
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RE: testing magneto ignition
ORIGINAL: Charley
Those wires kill the ignition if they are connected to the case. You kill the ignition by grounding it. Open the switch and test for a spark.
CR
ORIGINAL: dditch
Could not see a spark. Turned the lights down some too.
The black coil box has 2 wires that go to the engine case.
One directly to it, the other goes to it through the ignition switch.
Both test good continuity to the case.
Could not see a spark. Turned the lights down some too.
The black coil box has 2 wires that go to the engine case.
One directly to it, the other goes to it through the ignition switch.
Both test good continuity to the case.
CR
Also, Q-75 mags like to have minimal clearances between the mag core pieces and the flywheel. I usually set mine between .006" and .010". Thats just the thickness of heavy bond paper or a thin business card. These will only make a spark when turned quite rapidly .... slow prop flipping won't produce a spark.
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RE: testing magneto ignition
Doh!
You guys got it right. I did not label the kill switch when I built the plane. I was thinking of it as an On switch.
I realized that this morning as I was waking up and went downstairs to try it and I have a spark after all.
now I have a carb issue I think (another post)
You guys got it right. I did not label the kill switch when I built the plane. I was thinking of it as an On switch.
I realized that this morning as I was waking up and went downstairs to try it and I have a spark after all.
now I have a carb issue I think (another post)
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RE: testing magneto ignition
[quote: Truckracer]
On the Q-75, the lug on the mag coil nearest the iron core is grounded ... usually to one of the mag retaining bolts. The other lug, and a larger one located farther from the core is the kill connection and like Charley wrote, kills the engine when grounded.
[/quote]
Thanks for the correction. I've not seen the Q-75. Should have confined my answer to how the switch operates.
CR