750 SFC Electronica ignition module
The original Bosch ignition fitted on the SFC Electronica was special for this model. When these modules came later out of stock,
the factory decided to use the same # 034 ignition box as fitted on the late 1000cc 180 (with Nippo Denso alternator), Jota 120
and RGSs. This new module has exactly the same performances than the older one, however the timing is different. meaning that
the woodruff key (of the rotor) has to be removed.
The factory advised to machine in the rotor a new groove for the woodruff key, however most of the time the key was simply
removed and the rotor was timed only by tightening its nut, secured by a toothted washer.
Ignitions 1000/1200 LAVERDA :
* BOSCH HKZ (1973 – 1978) :
The original Bosch ignition of the 1000 Laverda is a source of various problems, above all the first serie HKZ. If you have not yet
replaced it by a good system like the IIS (see page improving), here are the main points to check on a Bosch HKZ system.
However keep in mind that this ignition is the first thing to change on a 1000 Laverda. See the improving page
– Checking the original Bosch HKZ ignition (1000)
– Check the ignition coils: Disconnect the black wire (bikes before the end of 1973) or the red wire (bikes after 1973) from the
junction box under the tank. Connect an ohmmeter tothis wire and to earth. Resistance should be of 250 to 400 ohms. If not,
change the coil.
– Check the pick-ups: For bikes before the end of 1973, disconnect one of the violet wires from the junction box under the tank.
Connect an ohmmeter to this wire and to earth. Resistance should be less of 100 ohms. Check the other violet wire. If resistance
is higher than 100 ohms, change the stator. For bikes after 1973, disconnect the two wires coming from each pick-up. Connect an
ohmmeter to these wires. Resistance should be less than 100 ohms. If not, change the stator.
– Checking the original charging system (1000)
– Disconnect the yellow/black and the yellow wires from the junction box under the tank (two yellow/black wires for bikes before the
end of 1973). Connect an ohmeter, resistance should be very low. If there is no resistance or, at the contrary, a very high resistance,
change both charging and lighting coils.
– Checking the Bosch rectifier
– Disconnect the two red wires and the earth wire on the rectifier. Connect an ohmmeter (+ and -) successively to the two positive
and to the negative, resistance should be very low. Reversing the ohmmeter connections, resistance should be infinite. If not, replace
– If ignition problems
1- Ignition switch on ON? If yes:
2- Check ignition coils. If OK:
3- Check pick-ups. If OK:
4- Check stop engine relay.
* BOSCH BTZ (1978 -) :
The BTZ has a better reliability, even if the ignition HT current voltage is still unsufficient. One again, replace it ASAP by a modern
Some starting problems, often followed by a detonation into the exhausts often mean a failure of the ballast resistors. A good way
to solve the problem is to shunt the resistors. In this case, the module looses its protection against the HT current, but I know several
bikes which run ok without these resistors. Your own choice though.
Another common problem is that the ignition modules are not perfectly grounded. Check the connexion and, if necessary, connect the
earth wires directly to the battery negative.
– Checking starter motor (1000)
- BreganZane – Live Laverda!
- ILOC (Laverda) – Buying a Laverda
- Laverda 750S Formula (1999)
- Wrenchmonkees Laverda 750
- Www.sv650.org – Suzuki SV650 / SV650S web – DECEMBER 1999 ARCHIVE