I have a 1975 Model 137 Bultaco 250 ALpina it is a US model. I rewired it to spec the brake lite switch is new and the resister is good. My problem is soon as I hook the ground up I lose spark what Iam I missing. :bang:
Bultaco 206 yes I have spark until I hook up taillite ground. The leonelli switch box is rust free and good shape. ? The high beam indicater lite wiring shows blue/white wire as being ground and red power but its oppisant of the rest of the wiring aaaagh.
OK, then your 'new' ground sounds like it's causing a dead-short. I only ever had one Alp with lights (M99) and I don't remember the switch having its own ground. Hmmm...