Engine Burning?

I think the first question folks will ask is abt your kill switch...
What are you using?

Second question will be abt the status of that white wire...
Do you have it capped off nicely?

It is odd that two have gone bye-bye in succession...
I'd start with the above and take it from there.

Good luck
rc

I know he just said he wasnt using a kill switch, but if he had been, wouldnt it be connected to the white wire?

motor_bike_fanatic said:

I know he just said he wasnt using a kill switch, but if he had been, wouldnt it be connected to the white wire?

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You can but you shouldn't. The white wire is a 6 volt line ment to run a headlight. Shorting out the circuit through what is supposed to be power to the lights just isn't the right way. Your kill switch's two leads go to the wires from the CD, one killswitch wire to each CD wire. That way your shorting out the CD circuit.

If your not going to be using the lighting circuit then tape off the white wire

The soldering of the magneto's coil lead that goes to ground is often a cold solder joint. It is possible that this joint opened up due to vibration.

A simple resoldering of the lead might be all that is needed to repair those magnetos that are not working.

jowens said:

Would it look broken because on both of the magnetos I have replaced the coil lead looks fine...?

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The easiest way to check is with an ohmmeter between the blue or white wires and the magneto metal body. If no continuity, then you know that there is an open circuit for the ground.

jowens said:

Thanks for the help rohmell, one last question if it proves to not have continuity but the solder looks fine how do I go about doing re-soldering it......in other words how do i prep it....getting rid of the crappy solder...heat it and melt it off?

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Reheat the connection so that the solder melts, carefully lift up the lead and see if it is clean, it might have insulating varnish on it, clean with sandpaper or razor blade. Reheat the solder until it melts, adding fresh solder helps, insert lead into molten pool of solder and let cool. To overcome the thermal mass of the magneto, you have to use a large iron or gun, around 100W or so.

A cold soldered joint can still show continuity when tested with a meter, but exhibit a very high resistance to electrical flow when the component is expected to operate.

jowens, unless the cold soldered connection was executed exceptionally bad by the factory worker it will appear to the naked eye to look nearly identical to a properly soldered connection.

Well if the mag does not work, what do you have to loose trying to fix it?
I all honesty though, I have worked with electronics for 31 years and repaired motorcycles for 29 years. I have seen (and made in my early years) plenty of poorly soldered connections that looked perfectly good.

The other connection that is known to fail is where the blue wire attaches to the lead coming out of the mag's windings.

Solder joints sometimes take a trained eye (and good eyes) to see the fault, sometimes cold solder joints can look perfectly good. Like someone else said, you already counted the magneto as dead, so why not poke at it and try to fix it? You have already been given good advise on technique, I might add that it seems prudent to pay extra attention to the lead that solders to the core of the magneto, that is where the black wire gets its connection and where the ground hits the motor.
I can't find my notes from when I had a magneto on the bench, but I think it measured something like 300 Ohm Black to Blue, and 30 ohm black to white. Not 100% sure on those numbers but I think that is in the ballpark, (black to white might have been even lower) I have heard enough about poor solder joints on magnetos to suggest this might be what you have going on here. If you do have a bad solder joint the resistance measurements would reflect higher numbers. But not necessarily, as things heat up and cool down these connections sometime make better or break cause metals expand/contract when they heat and cool. If you take your dead magneto and measure the resistance (at coil wires, not blue to black) and read something around 300 ohm then the magneto coil is probably OK and you just have bad solder. Also, I noticed that the wire used on these magneto's is total crap. I couldn't even get it to hold together after twisting. Sometimes crappy wire like this doesn't like to take solder, you might be better off getting some quality wire to replace the three wires on your magneto...