Stopping the engine

[AdrianJ]

Back for help again.
After so much trouble starting my plunger A10 and then keeping it running, you’ve guessed my next problem - stopping it.
The kill button was working fine, but now suddenly it has stopped working.
To check it I removed  the magneto end cap and tested continuity between the brass work in the end and the frame when the button was pressed. This seems to be OK. I was guessing that the spring contact in the magneto cap is perhaps a bit week, but I wanted to check with the forum before I go spraining any springs or contacts.
Any thoughts or suggestions would be gratefully received.
Adrian

[chaterlea25]

Hi Adrian,
Take a piece of wire and connect one end to the magnetos body,  with the engine running touch the other end to the centre bolt of the points where the cut out contact rubs. Engine should stop!
If it does not check out the earth brush(s) as in the recent thread

John

[AdrianJ]

Thank you - will try that tomorrow.

[muskrat]

G'day AJ.
Ha, that brings back memories. Not long after I got my A7 plunger going I had the same problem. Back in the early eighties, no internet, new to magneto ignition. Ran like a dream but couldn't stop it!
I eventually found the earth brush was gone. Living in the bush and needing to ride I found the carbon rod inside a C size battery was close. Ground a little groove for the spring and hay presto all worked great. I rode for about 10 years with it!
I'm not saying you should try it as replacements are available, but back in the day we did what we had to.
Cheers

[AdrianJ]

Thanks very much folks it’s sorted now.
Yes the wire to earth stopped the engine. Ta John.
I’ve just bent the spring in the cap a bit and we seem to have proper contact.
Stops a treat now.
Now all I have to do is get it warm enough to set the carburation properly.
Shouldn’t need an earth brush for a while Musky - the mag has just been rebuilt, but I’ll bear the battery rod in mind.
Adrian

[Butch (cb)]

Conversely, when I first bought mine ('79) the threads on the cap were knacked and it would fall off. This coupled with a 6 spring clutch so recalcitrant that I couldn't find neutral when I stopped in gear meant I'd just stall it to stop the motor. All a bit barbaric really. 

[AdrianJ]

Threads?? 

[Swarfcut]

Adrian, as yours is an early coal fired bike, it sounds as if it has the bakelite clip on magneto end cap. The butcher has the later aluminium screw on type, famed for the ease with which it can be cross threaded to the technical term quoted. Hence "threads".

 Your cap may have an O ring seal, if this is a bit too thick it will hold the brush too far from the rotating points bolt.  To be expected with repro parts, made just not quite right. Worth making sure the points bolt has a nice smooth head, any nicks or gouges will machine away the tip of the carbon brush.

 Swarfy.

[AdrianJ]

Hi Swarfy,
 The “threads” bit was a weak joke.
I’ve had both - used to have ‘61 flash.
I think that the O ring may indeed be the culprit. I’ll check the points bolt.
It’s nice to have a simple solution for a change.
Adrian.

[muskrat]

G'day AJ and all.
Bugga, just reread the posts. I'll have to wait till the triple coffee kicks in at 5am in future.
I was thinking of the "other" earth brush. under the screw at the other end of the magie.
Sorry fellas.
Cheers

[RichardL]

I believe another possibilty for the "kill brush" standing off the center bolt could be the cam ring not seated home.

Richard L.