The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: Marqs1979 on 01.02. 2016 21:00

Title: Kill switch
Post by: Marqs1979 on 01.02. 2016 21:00

This black cover on my k2f magnet should probably connect to a kill button and then linked to motor ???
The engine does not die when I connect the cap to the engine . Have I misunderstood something ? Or what could be wrong ?

http://forumbilder.se/F8SKM/20160201-185457.jpg

Title: Re: Kill switch
Post by: Marqs1979 on 01.02. 2016 21:02

the cap is new and looks to be in good condition

Title: Re: Kill switch
Post by: trevinoz on 01.02. 2016 21:04

Check that the carbon contact in the cap is touching the centre screw.
Check that the cut-out switch has continuity to frame.
Check the earth brush in the top of the magneto at the drive end.

Title: Re: Kill switch
Post by: Marqs1979 on 01.02. 2016 21:09

I have no button yet, but tested by a cable stub to the engine. I tested even without the lid and put the cable directly to the screw.

Title: Re: Kill switch
Post by: trevinoz on 01.02. 2016 21:11

I would look at the earth brush.

Title: Re: Kill switch
Post by: WozzA on 01.02. 2016 23:02

You DO have a earth wire connected to the cap & kill switch....  dont you?   *????*
Your picture does not show one..

Title: Re: Kill switch
Post by: Marqs1979 on 02.02. 2016 05:24

I'll install a wire and button now. I have only tested a temporary cable.

Title: Re: Kill switch
Post by: Marqs1979 on 03.02. 2016 11:48

Can add that I use EasyCAP capacitor, can it affect so that the short circuit does not become properly?

Title: Re: Kill switch
Post by: groily on 03.02. 2016 15:09

Won't be the capacitor, no - that doesn't get in the way of the head of the centre screw for the contact breaker. The risk is the other way - ie if the centre screw touches the earthed side of the capacitor, the magneto won't work
If the magneto's main earth brush isn't functioning for some reason you may in some circs get a shock, or see sparks off the screw when you earth it, as the earth brush's job is to provide a return path for the HT current. As Trevinoz says, best check it's working.
I'd give the head of the centre screw a good clean, check there is continuity between the wire off the end cover and the brush or pad inside it that is supposed to touch the screw, and that there is permanent contact between the two. It's odd that a direct link from screw head to frame doesn't stop it, but these things can be sensitive sometimes.

Title: Re: Kill switch
Post by: Marqs1979 on 03.02. 2016 18:20

Hey! I tried again! this wire directly to the center bolt and the engine continues to run perfectly .


http://forumbilder.se/F8SQT/20160203-191300.jpg

Title: Re: Kill switch
Post by: Marqs1979 on 03.02. 2016 18:43

When you write about the earth brush, you mean the black tip in the middle of the lid ? Must assure me that I understand everything right.

http://forumbilder.se/F8SQT/20160203-191323.jpg

Title: Re: Kill switch
Post by: Billybream on 03.02. 2016 19:09

I,m not familiar with the bakerlite cap, as most are alloy, but I think your brush is stuck, as it should be spring loaded and protrude out into the magneto.

Title: Re: Kill switch
Post by: trevinoz on 03.02. 2016 20:10

Marqs,
              The earth brush is in the large slotted screw on top of the magneto at the drive  end.

Title: Re: Kill switch
Post by: Marqs1979 on 03.02. 2016 20:17

Thanks :) I will examine it tomorrow :)

Title: Re: Kill switch
Post by: Marqs1979 on 04.02. 2016 14:45

The mystery is solved :) probably have to get a earth brush :)
Thanks for your help and your patience :)

http://forumbilder.se/F8STT/20160204-153355.jpg

Title: Re: Kill switch
Post by: Marqs1979 on 13.02. 2016 17:10

Now I have installed a new earth brush and it was a success :)
Thanks again for your help!

Title: Re: Kill switch
Post by: a10 gf on 13.02. 2016 20:44

Success stories always apreciated.