Author Topic: Smoking Wire  (Read 493 times)

Offline Magista

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Smoking Wire
« on: 16.03. 2023 23:41 »
When returning from a short ride I noticed smoke coming from this wire which I assume is for the magneto cut out switch. You can see the discoloration.

I assume this is a short I'll have to track down. If anyone knows of the top of their head feel free to chime in.

1958 A7 500 "Flash"
1973 Honda CL350

Online Colsbeeza

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Re: Smoking Wire
« Reply #1 on: 17.03. 2023 03:41 »
Hi Magenta,
Yes it is the magneto cutout earth wire, connected to your cutout button on handlebars. Unusual to short out - I am sure Cheeserbeeser (Andrew) will have an opinion. Another possibility is fuel leakage from the LHS tap caught alight, but then why did it go out?
Col
1961 Golden Flash
Australia

Online CheeserBeezer

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Re: Smoking Wire
« Reply #2 on: 17.03. 2023 08:16 »
Hi Magenta,
Yes it is the magneto cutout earth wire, connected to your cutout button on handlebars. Unusual to short out - I am sure Cheeserbeeser (Andrew) will have an opinion. Another possibility is fuel leakage from the LHS tap caught alight, but then why did it go out?
Col
Colsbeeza is correct in that it is difficult to see how current could be draining down this wire without, at the same time, the bike stopping. The wire is connected to the primary windings via the brush in the magneto endcap so. if current is draining down the wire sufficient to heat the wire the primary circuit must be shorted out and the bike would stop. Awaiting your further investigations with interest? Is the wire actually hot to touch?

Offline muskrat

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Re: Smoking Wire
« Reply #3 on: 17.03. 2023 08:47 »
G'day Magista.
In case it needs topping up. *sarcastic* *whistle*
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
Australia
Muskys Plunger A7

Offline Magista

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Re: Smoking Wire
« Reply #4 on: 17.03. 2023 15:47 »
Thanks for the feedback everyone. As always, it's appreciated.

The other possibility is I saw the smoke and assumed it was from the cut-out wire when in reality it was just a bit of oil burning off the exhaust...which honestly sounds more likely and I'm an idiot.  *doh* The discoloration may be just grime and I'm imagining the whole thing.

I'll fire the bike up again this afternoon, see what happens and report back.

1958 A7 500 "Flash"
1973 Honda CL350

Online Triton Thrasher

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Re: Smoking Wire
« Reply #5 on: 17.03. 2023 16:57 »
The magneto’s low tension current can’t burn a wire that thick.


Offline Magista

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Re: Smoking Wire
« Reply #6 on: 19.03. 2023 16:55 »
File this one under “Doh!”

It was just some oil burning off the exhaust.

Thanks everyone. 

1958 A7 500 "Flash"
1973 Honda CL350