Author Topic: k2f mag kill button  (Read 3543 times)

Offline Tumbleweed

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Re: k2f mag kill button
« Reply #15 on: 31.08. 2013 08:14 »
 just measured them properly and they are only quarter inch (sorry must be a bloke thing), i recently fitted a solid state reg, i wonder if thats the problem . tw
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Online Brian

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Re: k2f mag kill button
« Reply #16 on: 31.08. 2013 08:30 »
When you say they are BOTH about 1/4" long what do you mean ? There is only ONE earth brush, not two.

The one you need to check is at the front of the maggy under the screw in the picture I have added.

If this earth brush is ok then the fault has to lie with the brush in the cap or with the kill button itself.


Offline duTch

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Re: k2f mag kill button
« Reply #17 on: 31.08. 2013 11:01 »

 T-Dub, can't see how anything related to regulator will affect it ......? more the likely earth brush factor....
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Online Triton Thrasher

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Re: k2f mag kill button
« Reply #18 on: 31.08. 2013 12:56 »
When you say they are BOTH about 1/4" long what do you mean ? There is only ONE earth brush, not two.

The one you need to check is at the front of the maggy under the screw in the picture I have added.

If this earth brush is ok then the fault has to lie with the brush in the cap or with the kill button itself.



Don't some have an earth brush behind the points plate?

Offline wilko

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Re: k2f mag kill button
« Reply #19 on: 01.09. 2013 00:50 »
Yes.

Online trevinoz

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Re: k2f mag kill button
« Reply #20 on: 01.09. 2013 21:58 »
But not necessary.

Offline duTch

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Re: k2f mag kill button
« Reply #21 on: 02.09. 2013 09:11 »

 Amazing how many Brushes there are in a Maggie, 1 for each plug wire=2, + 1 earth brush + 1 cut-out/kill brush + 1 behind (some-Trev?) points plates.

2+1+1=4+1(?)=~5.....any more we forget about.??

     *smile* *eek*
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline Tumbleweed

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Re: k2f mag kill button
« Reply #22 on: 02.09. 2013 15:44 »
hi , everybody thanks for your input, it still wont stop ive looked at the things that were mentioned, exept i cant remember a brush behind the points plate, would it be easily seen when the plate is removed,and  is it a carbon brush    ? *conf*
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Online trevinoz

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Re: k2f mag kill button
« Reply #23 on: 02.09. 2013 22:26 »
The brass point plates had a brush on the rear originally but this was done away with when the steel plates came into use.

Trev.

Offline Tumbleweed

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Re: k2f mag kill button
« Reply #24 on: 03.09. 2013 21:21 »
thanks , this one has steel plate trev , its running so well just now i think i will settle for stalling it for the time being  i am glad the reg has nowt to do with that prob  *smile*  tw
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Offline KenF

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Re: k2f mag kill button
« Reply #25 on: 04.09. 2013 08:41 »
TW, if the engine will still run with the contact-breaker centre-screw shorted to the mag housing, then I think you're asking for trouble by not sorting it. The earth brush isn't doing its job properly. That could mean that the sparking plug return current is having to spark across one of the bearing insulators, which won't do it any good, and then pass from the bearing outer race to the inner race through the balls and grease between them, which in the fullness of time will wreck the bearing.

If you've got a multimeter that will measure resistance down to 1 ohm or less, then measure the resistance between the CB centre-screw and the mag housing. It shouldn't be more than about 10 ohms. If it is, do whatever you need to do to the earth brush and its spring to get the reading down to 10 ohms or less.

And once you've done that, you'll probably find your cut-out works again.

Best of luck,

Ken
http://www.brightsparkmagnetos.com

Offline Tumbleweed

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Re: k2f mag kill button
« Reply #26 on: 04.09. 2013 16:19 »
thanks ken, my next door neibour , came round with his multimeter, and it read 85.5 ohms, ive cleaned the earth brush again, starts first kick but still wont stop on the button *sad2*
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Online Triton Thrasher

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Re: k2f mag kill button
« Reply #27 on: 04.09. 2013 18:56 »
Is the earth brush spring making poor contact with the little cupped screw it sits in? Rust, grease or something in it?

Offline wilko

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Re: k2f mag kill button
« Reply #28 on: 05.09. 2013 00:23 »
Can't wait to get to the bottom of this?

Offline KenF

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Re: k2f mag kill button
« Reply #29 on: 05.09. 2013 06:51 »
85 ohms is the problem, TW. As TT says, check that the spring-to-cup contact is good. If it is, then the 85 ohms suggests, as British Rail might have said, that your earth brush is the "wrong type of carbon." Send me your address to ken@brightsparkmagnetos.com, and I'll pop a replacement in the post to you. Or if you'll be at Netley Marsh on Friday or Saturday, come and see us in the marquee.

Ken
http://www.brightsparkmagnetos.com