Ducati Elettrotechnica magnetos, 90mm id flywheel, were on 1974-1982 Tomos (early A3 engine), 1970’s Morini S5K2 (Marina Mobili part number 29-0026), and maybe others.
ZEM magnetos, identical to Ducati, 90mm id flywheel, were on 1983-85 Tomos (A3 engine).
These magneto-generators are 3-wire external ignition ground type, like most Italian made US-model mopeds. Like many other US-model moped magnetos, the brake light is powered by the ignition source coil ground. This was to meet the US DOT requirement that the headlight not get dim when the brake light was on. So the two-coil generator has three outputs, the black ignition wire from the points to the spark coil, the blue ignition ground wire that is grounded through the brake light or brake light switches, and the yellow light wire the provides 6V AC about 25 watts for light and horn.
Early Tomos 1974 to 1985 had this type of magneto, with the brake light switches wired in series and normally closed when installed. If you removed the tail light and squeeze either brake, the engine would die. Starting in 1986 Tomos improved the electrical system with a solid-state-regulated single lighting yellow wire, a ignition black wire, and an internal ignition ground. So the engine never dies, on a 1986 and later Tomos with the 2-wire Iskra magneto, when the tail light wires are unplugged and the brake is applied. When the magneto type changed from 1985 to 86, the wiring also changed.
These Ducati and ZEM 90mm magnetos will interchange with 90mm Bosch and other Bosch compatibles like Iskra, except for the width and position of the key groove that determines the ignition timing. They are counterclockwise rotation. Points are CEV type “right hand” (the brown part looks like your right hand sideways with fingers bent). Condenser is CEV type.
Tomos mopeds have been equipped with many different magneto names and types.
1974-82 A3 Ducati 3-wire (pts, ext. ign. gnd) 3-hole stator
1983-85 A3 ZEM 3-wire (pts, ext. ign. gnd) 3-hole stator
1986-93 A3,A35 Iskra 2-wire (points,2-coil), 3-hole stator
1988-89? A3 CEV 2-wire (points, 2-coil), 3-hole stator
1992-93 A35 IDM 2-wire (points, 2-coil). 3-hole stator
1993-95 A35 IDM 2-wire (CDI, 2-coil), 3-hole stator
1994-95 A35 Iskra 2-wire (CDI, 2-coil), 3-hole stator
1996-06 A35 Iskra 2-wire (CDI, 4-star), 2-hole stator
2002-04 A35 Iskra 3-wire (CDI, 4-star), 2-hole stator
2005-07 A55 Iskra 4-wire (CDI, 4-star, external pulser)
2005-07 A55 Iskra 5-wire (CDI, 4-star, external pulser)
2008-13 A55 Kinetic 5-wire (CDI, 4-star, ext. pulse coil)