Periodically, someone asks how the pick ups must be connected once
disassembled and possibly rewired. Here's the final word, keep this as
a reference:
The vertical head pickup is the one in front of the flywheel, the
horizontal head one is below the flywheel. Since the flywheel turns anti-clockwise, seen from the left side of the motor, the vertical head pickup will fire first, the horizontal head pickup will fire after 90°. The spark plugs on the Pantah fire each turn of the crank, so there's a "wasted spark" each cycle. The "good" spark for one cylinder alternates with the wasted spark for the other. If you off-time one camshaft of 1/2 turn, no matter which camshaft, no matter in which direction, the motor will still run, but the timing will not be 450°-270° any more, but 630°-90°: a big bang Pantah.
There are two cables connected to each pickup. They are both marked "V"
for VERTICALE and O for "ORIZZONTALE" at both ends. The markings are on
little plastic rings that may well be missing after over 20 years. the 4 cables run inside a common rubber sheat to a 4-pin connector under the tank, that joins to the wiring that then connects to the Bosch BTZ modules and the coils.
At the pickup end, the wires are both the same colour, usually black, but they are not interchangeable! At the connector end, one wire for each pickup is green and one green with a black stripe. So if you look at the connector, you will see a green wire and a green/black one with a little ring marked "O" and a green and a green/black one with a ring marked "V". The female half of the connector cannot be fitted inverted to the male half: if you look at it from the pins side, you will see that it has a V shaped notch at one side, between the two wires, and two corners cut of at the other side. Still looking at the female half connector from the pins side, the cables are as follows: top left: V-green/black; top right: V-green; bottom left: O-green/black; bottom right: O-green
In order to remove the pickups from the motor, or fit them back, the cables must pass through a hole in the engine LH case. Once the cable goes through this bolt, the passage is made oiltight by a rubber ring compressed by a plastic nut. The plastic nut screws into a brass nut which is very tightly fastened to the crankcase. The brass nut has a 21 mm hexagon head (13/16" or spark plug wrench size) but it's very shallow and not easy to remove. The best way to remove and fit back the pickup cable is to remove the cable ends from the 4-pin connector, which requires a special tool. It can be also done with a very small screwdriver, the kind used for eyeglasses: fit the scrwdriver between the plastic connector and each female pin, at the two sides of the "slit" in the pin. This will flatten the two "wings" that hold the pin in place. Now press the pin from above towards the cable and it will
slip out. To re-fit, just carefully pry open the "wings" again.
Luca
