BTH magneto contact breakers

[tractorman]

Hi, I got interested in a job lot of BTH magneto contavt breakers on ebay recently. I left things to the last minute and then had a re-read and noted they were for AG4 aircraft magnetos. They certainly look like those fitted to KC2 mag offen found on pre-unit Triumphs but I left myself with no time to ask question, so I backed off from bidding. Does anybody know if these are interchangeable ?

[chaterlea25]

Hi tractorman,
All the BTH contact sets seem to be the same, the brass rotor plates are marked R and L which is the rotation looking from the drive end, ( this can be somewhat confusing  as the L plate turns clockwise (righthand) when looking at the points end 

HTH
John

[tractorman]

Hi John, thanks for the reply. sorry I took so long to respond. If I see these aero contact sets for sale again I shall find out more. I never trust the rotation marking, always look at the arm trailing on to cam for correct rotation.

Bernard