Cut out switch on magneto

Information relating to the Matchless G11 or AJS Model 30 600cc twin
Locked
match53
Posts: 3
Joined: Wed Oct 12, 2005 10:45 pm
Location: CO DURHAM UK

Cut out switch on magneto

Post by match53 »

Hello

This my first time on this or any forum, so I hope you lads and lasses can help. I am very new to the world of Britsh and clasic bikes, been brought up on Japan's finest,push button-go-stop.
Good but not much character,nothing to tinker with, so after looking at some old photo's of my father on his 1953 G3l took the plunge.
great so far met lot's of people willing to help an offer free advice. Anyway.... this is probably the most easiest of fixes to other people but when you are out of ideas you call in the cavalry.

I have just purchased a lovley 1957 G11, but I am unable to stop the engine.I belive you simple push the cut out switch and hold it depressed until the engine pitters out. On my previous bike 1958 G3 it was fitted with a cut out switch on the handle bars.
I have taken the outer cover off the magneto and the push is spring loaded mechanisum works fine. it seems to bottom out on a chrome bolt head. i have looked through a few manuals but I am completley stumped.
Any help would be appreciated.

Cheers

Match53
itma
Posts: 7721
Joined: Tue Nov 22, 2005 6:01 pm
Location: UK

Cut out switch on magneto

Post by itma »

you should be able to stop the engine by pushing the button on the end cap of the magneto.
If that don't work, [are you pushing hard enough?] then something is missing, maybe the carbon brush behind the rotating plate?
lawrence
Posts: 2453
Joined: Mon Jan 01, 2001 12:00 am
Location: NORTHAMPTONSHIRE UK

Cut out switch on magneto

Post by lawrence »

Hi David

Welcome to the forum!

Take a length of wire (bare at each end). With the engine running touch one end of the wire to the brass nut on the mag cover and the other end to earth (e.g. the engine).

The engine should immediately stop. If it does then you have a break in the cable between the cut-out switch and the mag.

If the engine doesn't stop then the mag needs looking at.

Once you have done this test let us know the result and lots of advice will follow from all the posters.

Most will be conflicting but that is part of the fun!
Don Madden
Member
Posts: 2882
Joined: Mon Jan 01, 1990 12:00 am
Location: USA USA

Cut out switch on magneto

Post by Don Madden »

If he has the correct mag on his G11 it does not have the brass nut for an external kill switch. It was originally fitted with the cap described above with the push-to-kill button in the center of the cap, & it should have the brush inside as stated. There should be a brush behind the contacts if fitted with the original brass contact set but there is another earth brush at the drive end. The main function of these brushes is to prevent earthing through the bearings but they also improve the spark reliability. I have seen one such end cap that someone had insulated the button thinking it was a good idea. It wasn't.

Cheers, Don.
laxy
Member
Posts: 790
Joined: Sat Jan 01, 1994 12:00 am
Location: LINCOLNSHIRE UK

Cut out switch on magneto

Post by laxy »

Hello David, how fortunate you are to have an engine that wont stop,
most of us would love to be in that position.
If you do a search forum for magneto repairers one of the several companies that do this work can advise you over the phone.
They may even sell you the bits you need to do the work yourself.
It does sound though as if the little round piece of carbon in the end cap itself is missing.If this is the case you can maybe make one from an old dynamo brush.
In the meantime keep putting your hand over the carb to kill the engine.
MikeM.
Member
Posts: 1906
Joined: Wed Jan 01, 1992 12:00 am
Location: SURREY UK

Cut out switch on magneto

Post by MikeM. »


Check the brush next to the timing case, I had a problem with stopping the engine on my Model 31, it was caused by the said brush being oily due to the seal in the end of the mag case leaking. It's one of the jobs to be done when I strip the twin down this year (hopefully).
pkr87
Posts: 592
Joined: Thu May 06, 2004 1:00 am
Location: KENT UK

Cut out switch on magneto

Post by pkr87 »

Hello Mr. 53,or may I call You Match.I hope you are having success with your problem.One bit of advice I would not follow is to kill the engine by putting your hand over the carburettor,all you do then is to drag lots of fuel into the engine which washes oil off the bores and the fuel ends up diluting the lubricating oil.A better way to stop the motor would be to let it tick over and then stall it in second gear.Hopefully you will sort out the mag and not need to do that.Happy riding Paul
match53
Posts: 3
Joined: Wed Oct 12, 2005 10:45 pm
Location: CO DURHAM UK

Cut out switch on magneto

Post by match53 »

Many thanks to you all for your quick replys. Unfortunatley I have not had time or the best of weather to try out some of your ideas. I have managed to take a couple of photo's of the mag cap and inards. The spring push button seams to be contacting on the chrome bolt head in the center. As some of you have suggested , that some carbon brush may be missing.... is this on the end of the cut out button or on the chome bolt head and is the chome bolt o.k. in this loctaion..?? Not sure how to put photo's on a forum as yet,but if anyone would like to contact me use the PM service and I will try to send photo's that way.

Cheers for now

Match53Edited by - match53 on 05 May 2009 7:46:25 PM
itma
Posts: 7721
Joined: Tue Nov 22, 2005 6:01 pm
Location: UK

Cut out switch on magneto

Post by itma »

email address not a good idea best edit it out asap
use the PM facility
match53
Posts: 3
Joined: Wed Oct 12, 2005 10:45 pm
Location: CO DURHAM UK

Cut out switch on magneto

Post by match53 »

Just little note to update you on the stopping problem with our G11. I purchased various bit's for the magneto from 'jampot spares' and low and behold it was the earthing brush that was the problem. As I said previously we had fitted a second handone but it obviously was either faulty or short. Anyway we now have a cracking bike which starts and stops.
Many thanks to the members that wrote in with various suggestions, all very welcome and appreciated.

Cheers
Match 53
Locked