On the other hand, click it into second gear, roll backwards until at the good side of TDC, back to neutral and give her a kick.

email (option): cas.vanderwoude@gmail.com

Ian, Cas and Michiel are absolutely right. The valve lifter reduces strain on the valve train when starting. It's not just about being a hairy-arsed biker who can kick anything over.

Anyone who intends to use a WD motorcycle for the purposes for which it was intended should watch the 'Army Motorcycling' films and understand how a valve lifter can be utilised in assisting the negotiation of a difficult, slippery downward slope.

We are privileged to own something which, in its day was almost more all-terrain capable than any other vehicle available. Any modern-day owner who wishes not to avail himself of that potential is of course free to do so...but for me at least, sharing the experience of those who rode them for real more than seventy-five years ago is part of what it's about.

That said, any hint of 'bobbing' and wrapped exhaust pipes is enough to make me reach for the Boys Rifle so perhaps I'm not typical.

I ran a B31 for years without a decomp but I would recommend putting one on. It isnt kicking it over that is the issue which is definitely easier with decomp but it is killing the engine in emergencies. There is the risk of fire especially with no air cleaner, broken clutch cable which has happened to me several times in busy traffic and stuck throttle either because of carby issue or kinked cable for whatever reason. Im sure there are other reasons that I cant think of at the moment. You dont want to be reaching down for the spark plug lead to kill it especially in wet conditions.

It seems the list of reasons for fitting a valve lifter is a lot longer than the list for not fitting one....

Not having one has to be a compelling argument for the latter though... ..Ian

email (option): ian@wright52.plus.com

Think that about sums it Ian

Careful, there are more than 10,000 volts in there. If you don't set it up right and do the kill procedure right each time, you're liable to get zapped. A magneto ignition is not the same as a regular coil ignition. In the latter the kill switch shorts the low-voltage primary circuit, not the high-tension spark wire. Also, if your switch and wiring are not right the spark may jump the switch contacts or the wiring when operating, instead of the spark-plug gap. This would be bad enough if it jumps all the time (engine doesn't start) but what often happens is that the shorting out of the switch or the switch wire happens intermittently, usually at high revs. If you don't keep this potential problem in mind it will drive you crazy to find out why your engine is coughing.

Obviously, I see no shame in stalling out a 70-year old engine, having done it hundreds of times myself. BTW, no one will notice.

email (option): jonny.rudge@verizon.net

BTH racing mag's have a machined alloy points cover with a carbon brush in the center that runs on the points (low voltage)- you fit a wire from this via a stop switch to earth.

I have seen a similar system for the Lucas face-cam mag. with the brush bearing on the center mounting screw - i think it worked?

It works on my 'non racing' BTH fitted to the TRW... ..

Also fitted to early Lucas K2F mags as used on the A10 etc....

Do these earth the high tension side though?....Ian

email (option): ian@wright52.plus.com

A while back I had for the first time assembled the magneto (new bearings, brushes, points and so on) and mounted a piece of ignition wire to it. I was sort of pondering what would be a good way to connect it to a drilling machine or something to make it spin and find out if it worked. As I was thinking and looking around me I was sort of absent mindedly slowly turning the magneto by hand and ZAPPP! Not the first time I've been zapped by electricity I can tell you, but the first time I tested a lucas magneto on my left hand fingers.

Having just done this work I of course know that it works differently than a coil ignition. Have not yet figured out how to make a kill switch but something along the lines described above was what I had in mind.

Not a question of shame, it just feels a bit unsofisticated.

Thought i'd seen a similar arrangement on other machines.

I don't think they earth the high tension side, as a standard ignition cut-off (better still a jet-ski one) works without any arc'ing to earth.

Mind you even the 'low' tension side can show ~300v when running ....

We only fit them because we have to - for any machine racing, most of the time they are not actually connected as they cause so much trouble.

You got any links to where I can obtain one of these? (still thinking of building my own though)

/s

They were never fitted to magdynamo mags as used on the M20...Ian

email (option): ian@wright52.plus.com

Was more thinking more along the lines of the ones for jet-skis that was mentioned. All this is just me letting my thoughts wonder of really... best option appears no doubt to be fitting the compression release. If I can obtain one at a reasonable prize that is.