B31 ignition

[phil bsa b31]

Hi have had my mag refurbed by tony cooper when I turned engine over I got a good spark my question is how do I turn off bike as spark is constant can and how can I fit some sort of engine kill switch  any help would be great
Thanks Phil

[TGR90B]

There should be a wire connection on the end cover of the mag. Earth this & it will cut out. Normally a pushbutton on the handlebar acts as the kill switch. No wire connection & I'm not sure, but it's something on that principle.

[chaterlea25]

Hi,
Usually no magneto cutout on a Lucas MO1 magdyno
I saw a "new" type of points cover for sale recently that has a cut out wire/ brush assembly
I don't remember where though???

Anyway the method of starting and stopping a B31 and most other Brit singles is to use the valve lifter 

John

[TGR90B]

I was only relaying what was on my Douglas MK5 magdyno. It also strikes me that a cut out button is quite handy if you get a jammed throttle.

[phil bsa b31]

Hi john had  thought it was valve lifter just was fishing for ideas on the possibility of fitting some kid of ignition might give tony cooper a ring tomorrow see what his thoughts are not sure I like the thought of it being unprotected  but a while away yet so plenty of time
Thanks again   Phil

[33d6]

I really feel old. I know modern bikes are moving further and further away from the old dungers we like to play with but both Phil and TGR90B have really hammered it home how far we've come when a modern rider  has to ask how to stop a B31.

Phil, you use the valve lifter not only to assist in starting the beast but also to stop it. You can also use it as an engine brake when creeping down a really, really steep and slippery slope. It is also the device of choice to stop the engine if you ever have a jammed throttle as TGR90B remarked on.

The art of using the valve lifter is applicable to all old big singles. Once learned it transfers across from make to make with no drama. It makes it easy to start, stop and ride any of them.

Keep in touch. I'd like to know how you get on.   

Cheers,

[iansoady]

I doubt if the valve lifter would actually stop the engine if the throttle was jammed wide open......

I would suggest to Phil that he tries to get an old copy of Motorcycles and How to manage them which goes into some detail of how to start & ride such machines. It's easy for some of us to forget that not everyone learnt these techniques at our fathers' sides.

[R]

I doubt if the valve lifter would actually stop the engine if the throttle was jammed wide open......

Thats an interesting comment, if you have an ES2 in your credits ?

Have you not tried it ?
Once the compression goes away, no amount of throttle will bring the fire back to life again ?
If the valve lifter only cracks the valve open a trace, may be a different story however.

[Rex]

I agree. Lift the valve and the engine free-wheels to a stop no matter how much throttle you give it.

[iansoady]

I doubt if the valve lifter would actually stop the engine if the throttle was jammed wide open......

Thats an interesting comment, if you have an ES2 in your credits ?

Have you not tried it ?
Once the compression goes away, no amount of throttle will bring the fire back to life again ?
If the valve lifter only cracks the valve open a trace, may be a different story however.

But that's all it should do. I've always found 1/16" is enough.

And yes, I have tried it (but not on the current Norton which is awaiting attention). It does lose some power however.....

[phil bsa b31]

Just a few points have been building and riding bikes some 45 years think maybe will manage a bsa b31 I know you can stop bikes on exhaust lifters have fitted many , I was looking for possibilities on some sort of theft deterant in the shape of possibly an ignition ,as we live in a world of crime especially motorcycles  I personally put many hours in any bike I build so don't really want some scrote nicking it yes I use locks chains etc just looking fore something else
But thanks for all comments and help
    Phil

[chaterlea25]

Hi Phil
When parked leave the ignition on full advance
Scroats do not know what manual advance is, so if the go to kickstart it you will find them laying on the ground or hobbling away  LOL
That is if they know what a kickstart is? 

Most bike thefts now involve loading them into vans 

John