The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: mike.loehr on 03.03. 2025 00:09

Title: A 10 K2F manual advance
Post by: mike.loehr on 03.03. 2025 00:09
 Thanks for adding me to the Forum:Having just purchased 1959 A 10 married to a Watsonian side car with manual K2F magneto advance.Is the slack position full advance or retracted position advanced?
Mike
Title: Re: A 10 K2F manual advance
Post by: Billybream on 03.03. 2025 05:59
Full advance is when the lever is fully retracted, ie tight, but make sure the slip ring is moving within the magneto, as the cable and  slip ring can stick, best to remove points cover and observe.
Title: Re: A 10 K2F manual advance
Post by: groily on 03.03. 2025 07:29
Actually, not usually! Slack cable will be full advance if the cable enters the magneto housing on the left hand (engine) side looking from the contact breaker end. This is the norm on A series bikes not equipped with an automatic timing device.
The point about checking the CAMring is free to move is good though, they can sometimes get jammed.
The engine note will change considerably according to the position of the lever on the 'bars if all is working as it should. It'll run faster advanced, and slower and flat-sounding at full retard.
In normal running, most people leave the lever fully advanced 99% of the time, using retardation to start, to avoid kickbacks. With a chair on, a bit of retard on hills under heavy load might be helpful though!
Title: Re: A 10 K2F manual advance
Post by: mike.loehr on 03.03. 2025 13:14
My cable is as you described,I believe the position is stuck in full advance causing kick back on starting and no change on engine sound in either position.Will inspect mag breaker end for operation.Appreciate the help.
Mike

Title: Re: A 10 K2F manual advance
Post by: Rex on 03.03. 2025 15:53
Could be the timing has been set wrong initially?
Title: Re: A 10 K2F manual advance
Post by: mike.loehr on 03.03. 2025 16:22
Will bone on the mag timing procedure and dig into see what'sgoing on
Mike