Hello,
I just bought my first Bultaco its a 1973 Alpina 350. I usually don't buy non running bikes, but this one was in such good shape I went for it. The PO was an older guy who was the second owner. The first owner was his long term friend. I remember seeing spark when I bought it and the compression seemed good when kicking it over. I rebuilt the carb and was hoping to hear it run, but now it doesn't spark. I attached some pictures, because I know you guys like pictures. It has a headlight, taillight, brake light, and kill switch. I don't know if they are stock or aftermarket.
My first move was to clean and tighten the wires going to the wire connector block. The white wire going up to the headlight was loose. It looked like it was grounded to the screw holding the wire block in place. To narrow things down, I disconnected the green wire to the headlight, the yellow wire to the headlight, and the grey wire going to the kill switch. Then I cleaned the wire connector block.
At this point I got a lit test light on the green wire that goes to the motor. I also got a light on the black wire to the motor but only with it disconnected from the terminal block. When I connect the black wire from the motor to the block with the coil connected the test light doesn't go on. I couldn't get a light out of the yellow wire.
I put my ohm meter on the coil. It was reading steady 3.6 from the plug wire. The measurements were jumpy from the black wire to ground but it would settle in at 1.1. There is no spark plug boot. The PO jammed some wire in the spark plug and wrapped it around the plug. Maybe that killed the coil. Who knows?
I read about the condenser getting hot and going out so I decided to check the points, condenser, and magneto. It turns out the PO had a spare condenser and magneto puller. Maybe he monkeyed around with it at some point. The insulation was a bit frayed on all the wires under the side cover. The yellow wire was a total mess (no wonder it didn't work). I changed the condenser, taped up the frayed wires the best I could, and put it back together.
The test light is way brighter from the green and black wires. I am getting a faint light from the yellow wire. I know the black wire is the key to getting this running but I can only get the light when the coil wire is disconnected from the connection box. I read that the green wire is supposed to go to ground the coil nut. When I touched the green wire to ground and it sparked.
I am thinking the coil is shorted. Does anyone know what type of coil I can put in it?