You need convert your bike to 12 volt operation before attempting to fit electronic ignition

Boyer don't seem to offer a standard kit for Lightweights, so speak to them first to make sure you get the right parts. The important ones are:

ROT00111 Rotor AJS/Matchless single

STA00156 NT1a 3" stator AJS/Matchless/Jubilee

A suitable 12V igniter box (I used a Micro Mk IV for Triumph/BSA singles)

In addition to the electronic ignition bits, I'd recommend fitting a new spark plug and suppressor cap (5000 ohms)