The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: bluejay on 11.07. 2011 23:09

Title: k2f magneto advance mechanism
Post by: bluejay on 11.07. 2011 23:09

Hi all, been having a kick back on starting my 53 A-10 G.F. pulled cover off and noticed weights were not retarding enough, assuming springs were the problem, I replaced them, but still have same problem. I restored this machine almost 20 years ago and just started to have this problem recently. The bike does not have a lot of miles on it, as I ride my Harley most of the time. The auto advance assembly seems clean and free from any grunge, I can put my finger on the gears and feel a bit of play. I do hate the thought of pulling the mag off,anyone have any idea what the problem could be?       Jim.

Title: Re: k2f magneto advance mechanism
Post by: Triton Thrasher on 12.07. 2011 07:50

A bit of teeth backlash is normal.


I'd be tempted to ignore it and kick harder.

Title: Re: k2f magneto advance mechanism
Post by: bsa-bill on 12.07. 2011 09:37

Agree with Triton Thrasher, backlash through the timing gears is normal, taken into account when timing by turning engine back past timing point then turning in normal direction upto timing point.

Quick fix as supplied to me by members of the forum (sorry whoever - memory) is to increase the points gap a little - 1 thou equals 2 degrees .

An occasional kick back is ok, shows your not far off timingwise

Title: Re: k2f magneto advance mechanism
Post by: bluejay on 12.07. 2011 21:38

Thanks for the input guys. something to think about, see pics this past weekend, sunday morning get together, (geezers on wheezers) good fun.     J.