The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: michael snellin on 08.05. 2013 17:01

Title: magnetos ???
Post by: michael snellin on 08.05. 2013 17:01
Hello , everyone, just wanted to know is there a difference between a manual/automatic mag, just that i was at a good jumble at the week end did not know what to do.????? urgh ! felt a bid of a fool really!! not having nothing, that came with the bike when i bought it.
Title: Re: magnetos ???
Post by: RichardL on 08.05. 2013 17:10
Manual mag has a plain drive gear in the timing box and a lever on the handle bars that you use to retard the timing duiring startup and advance it when driving. The automatic timing device is a version of the magneto drive gear that uses centrifugal force to advace the timing automatically when spinning fast. In this case, no lever on the bars.

Richard L.
Title: Re: magnetos ???
Post by: muskrat on 08.05. 2013 21:14
 To further Richard's post. On the other end a manual type has a fitting for a cable near/next to a pickup.
Title: Re: magnetos ???
Post by: BSA_54A10 on 09.05. 2013 11:43
The magneto is the same unit.
Manual advance had a different bolt on end.
Auto has a different bolt on drive gear.
And yes you can put both on a single maggy.
Bike beesa
Title: Re: magnetos ???
Post by: A10Boy on 16.05. 2013 14:55
Generally speaking "Iron" engines ie Golden Flashes have the auto set up and the sporty jobs, with Alloy heads, Rockets etc use the manual effort.