BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: Harker on 13 Nov, 2023, 12:06

Title: 1951 A10 Plunger ignition timing
Post by: Harker on 13 Nov, 2023, 12:06
I have a 51 Golden Flash and wish to check/reset my ignition timing. However, all information I can find refers to the machine having an auto advance/retard mechanism on the end of the shaft. Mine doesn't but has a manual advance/retard lever on the handlebars. Do I just set the lever to advance and then set my points to open at 11/32 BTDC or what? Can anyone enlighten me? Thanks
Title: Re: 1951 A10 Plunger ignition timing
Post by: Allan G on 13 Nov, 2023, 15:43
Indeed, regardless of whether your using a manual or an automatic advance setup, you need to set the advance mechanism to fully advance (in the case of an auto unit, you need to wedge the Bob weights open).

Then find your measurement down the bore and from memory set your mag points just opening.
Title: Re: 1951 A10 Plunger ignition timing
Post by: EDDIE SIMPSON on 13 Nov, 2023, 17:06
manual magnetos are much more rewarding when set up properly.
firstly see whether pulling the retard lever or pushing the lever advances the ignition. so leave the lever in fully advanced position then time the ignition as normal.
i retard to start then go to fully advanced until engine warms up [ a few miles ] then retard as per engine feel / feedback.