AJS & Matchless Owners Club

Hello again. The question this evening is does anyone know of a BTH type magneto which is suitable for a 56 model 18?

Many thanks, Chris

Not sure why you'd want to go that route especially Chris? I think your 18 would have had an SR1 and an auto advance unit as standard for that year?

But a range of 35mm spindle height magnetos could probably be got to fit - BTH MD1 being one of them that would go on almost for sure. (The 'almost' relates to the disposition of the mounting holes on the base: an MD1 body I have to hand has similar mounts to an SR1 body, also to hand, but there be variants pretty much for sure.)
The MD1 would probably come with manual advance. As would a Lucas N1, normally - apart from Lister and other stationary engine versions. They were fitted on 18s to '54. Later cylinder fins are cut back, I believe, to take the taller SR version, but I know precious little about singles . . .

While there are arguments for and against BTH being 'better', to be honest there's nothing at all wrong with the Lucas ones and there are far more of them floating about if your problem is not having anything at all. SR1s are far easier to maintain, with their static HT coil & rotating magnet, car type points and accessible condenser etc etc, than rotating coil ones like N1 and MD1 etc.

I've found the SR1 to be a robust piece of kit despite, in my early days, a complete lack of maintenance.

JohnnyB

A chap on a VMCC run today with a mid 50's 16M has had a new electronic BTH one on his bike for about 4 years and reckons its a great improvement, expensive though. https://www.bt-h.biz/BT-H-Magnetos/. fixing bolts are metric I think and require the head reducing though.

Oh - if you're talking about the modern BT-H spark generators, then this is the one you'd need I think. Or one of the other even more glamorous models up to and including the replica KD1 TT magneto.
Not the same company as the old BTH who made magnetos and much besides - although I notice they've used some of the model numbering. Whether that simplifies or confuses I'm not sure!
Somewhere between £660 and £720 beer vouchers plus transport by the look of it.

Thanks, much appreciated.