Could not get my Bultaco 370 to run any good at all, on my Electrex ignition.
Had it graphed by Small Coils in Geelong and it has variable timing curve going to 10 degrees at 1000rpm, up to 17 degrees at 3500 rpm then drops off to 8 degrees at 7000rpm - no good for Bullys.
The bike runs great on an old Femsa at 20 degrees flat (2.8mm btdc) right through the range.
They don't even make the systems in England, they buy in the things from Europe anyway, as I found out.
Want to buy mine?? Ha!