http://mgaguru.com/mgtech/electric/et098.htmSome early manufactures of MC and Car, used positive earth, but why keep this systems on out BSA´s ?
One reason could be originality, but is this enough to stick to this odd system ?
I consider rebuilding my BSA A10 SR to 12VDV, with at Alton generator, and it has a negative earth system.
Later on a digital ignition will be added.
After fettling with weak & feeble dynamos and magnetos for decades, I decided to change to a modern and stronger sparks.
Modern fuel with ethanol is not easy to burn with a magneto system.
And change to a modern power for proper lighting. By law we need to use running light all day in Scandinavia, and it strain the weak dynamo system.
Another benefit with 12V negative earth system, You can fit a AFR gauge and easily monitor if the fuel ration is correct at all throttle and load conditions.
6 Volt is hard on the switches, and getting relayes and bulbs for 6 Volt is getting harder..
6 Volt GPS units are not easy to get, and other electric systemt require 12 V with a negativ earth
So why keep with a positive earth electric system on the BSA ?