2nd bad magnedo and cdi in a week

When I get the wires straight I take a little RTV and seal the hole where the wires come out of the nylon bushing. This will keeps the wires from moving.
 
I had the same problem. It would run great for while then miss and ran very bad
and then some times it would stop.to make A long story short I put A ground strap
on it thet I got from A auto parts store.
 
weather I am burning or breaking the thin coil wire just between the the coil and the solider point, it only happens when I am going wot at full rpms. this would be when the magneto is producing the most electricity. I just don't know why it has been happening.

1 If it was because of the kill switch being between the blue and black why isn't my friends bike having this problem?
2 It wasn't moisture because I have it sealed up good with silicone.
3 vibration? I don't think so It isn't to bad especially with my auto chain tentioner.
4 Is the magneto just producing more electricity then that thin wire can handle when I am doing top speed, pushing those rpms? (possible?)

I don't know what other reason would this happen?
 
That's where you would expect it to go open-circuit from a short-circuit, (ie kill switch). It's the one spot on the coil where the wire isn't firmly touching other wire etc, allowing it to reach a higher temperature. Possibly, using the blue/black combo for the kill switch, you're weakening the wire at that point due to the high current flow during the short-circuit while the motor stops turning.
Then, it could actually fail at any time.
I re-iterate, for the last time, don't use the blue wire for your kill switch. The current flowing through this wire is much higher than that flowing through the white, while the kill switch is depressed.

This isn't a common problem, especially not twice in one week. Either you're getting bad parts or you're doing something wrong. (Not pulling on the wires or anything like that?) Otherwise, the one thing that stands out is your use of the blue wire from the ignition winding to short the magneto/CDI and kill the engine.

... Steve
 
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thanks I am going to run from now on with the white and black as kill and see what happens. I have had the same problem with magnetos from 2 different suppliers. so I its not the magnetos them selves. Ill keep in touch and (keep your fingers crossed) be able to say I am having no problems.
thanks everyone
 
This is what might have happened to my Flying Horse Motor. Ran great for 2 days and now the Magneto Coil is dead. I bet it is that little wire rattled loose. Going to look first thing in the am...
 
Found 2 Issues with Magneto on 66cc Flying Horse Magneto

I took the Magneto Coil Loop out this morning and found that indeed, that little tiny copper wire soldered to the Top Arm of the Magneto Coil had broken. Also found that the White Wire had damaged insulation, allowing the wire to touch the case inside. I will post photos later of the whole process of repairing these issues, which involved removing the White Wire entirely and using a new 10 guage Wire for the Blue Power feed to the CDI. She started right up so I took her for an 18 mile ride with no more electrical problems...
 
This is interesting. Is there a lot of ignition parts problems with the Flying Horse brand? They basically look the same as Grubees to me. What is the difference?
 
I don't think it is necessarily the brand, but how fine and tiny the wire is coming from the Magneto Coil and soldered to the Top Arm. Vibration from these 2-stroke Motors is pretty significant and I would think break any tiny copper wire such as this. I was just able to figure it out, luckily from reading many posts in this forum.
 
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