advance range

BSA A65 is fully advanced at 29 degrees and Triumps T120 and T140 are fully advanced at 39 degrees, if I remember correctly. However the Boyers say on the box TRIUMPH/BSA. What gives? They need to top out at different settings, so one size cannot fit all.

seattle##gs said:

BSA A65 is fully advanced at 29 degrees and Triumps T120 and T140 are fully advanced at 39 degrees, if I remember correctly. However the Boyers say on the box TRIUMPH/BSA. What gives? They need to top out at different settings, so one size cannot fit all.

Click to expand...

It can, as the ignition would normally be set to the particular full advance figure.
All my literature says 34 degrees full advance for A65, and Triumph Unit T120 and T140 are 38 degrees F/A so the difference may not be as much as you thought, consequently, a Triumph would be a few degrees more advanced at low rpm which might be what's required as I think the advance ranges of the BSA and Triumph AAUs were similar (around 12 camshaft degrees - 24 crank degrees).

The fully retarded figure, for starting and idling, doesn't have to be very exact.