Ducati350ontario wrote:graeme wrote:This is a mates alternator showing the self generating ignition coils, red and green wires.
I would assume that there should be a circuit there.
That sure looks like what I remember. I took detailed pics of all my parts,... but never back them up. (you can guess how the rest of this story goes)
The picture was helpful, its the first one I've seen where I can make out the wires on the coils. I'll wait until hans confirms some of findings on that running unit before I start tearing into it.
Thanks again.
The story continues.
I just did some measurements of resistance R and inductance L, one the CDI supply winding (stator coil), the CDI electronics box, and the alternator stator coil set as an extra service. I didn't repeat all the measurements you did, I list here only those which seem relevant for funktionality.
My results:
- CDI coil (red/green) R = ~370 ohms, L = ~760 mH
- CDI unit input (red/green and vice versa) R = <0.1 ohms, i. e. short circuit
Not important for the CDI, but useful for later reference in case of charge circuit failure:
- alternator coils (yellow wires) R = ~0.2 ohms, L = ~0.98 mH
During the installation procedure of STK-164 we realized some pecularities:
- there are no permanent magnets as single units inside the rotor. Seems to be a one-peice strip of compund material (magnet-Polymer), glued to the inside of the rotor
- the air gap between stator and magnet/rotor is surprisingly large (>2 mm), hence the stator coil set does not need a corresponding precise centering shoulder on the stator carrier plate. Centering is sufficiently performed by the mounting screws. At first, I was in doubt about this "excessive" gap and the missing "centering". But in a phone call with a technician at Electrex, this was cleared out. Fyi: the old Ducati alternator shows an air gap of ~0.5 mm.
- the quality of the connector set for the red/green wires (CDI power sopply) is indeed inferior. It's female receptacles do not latch in their slots in the plastic housing -> they get extruded from their seat in the housing when the connection of the 2 parts is done. Result: no electric connection of red/green, i. e. no power input for the CDI box, hence no spark! They must be pushed into their sets in the housing by a small screwdriver, in order to engage them with their male counterparts, until they make a reliable contact.
- the mounting "eyelet" at the CDI box immediately broke off into pieces when I tried to fix the box to the frame by an appropriate screw (only hand-tightened!). However, a cable tie solved the problem.
- the cables to/from alternator/CDI power coils and the CDI pick-up are made of single wires wrapped in a soft envelope made of some impregnated fabric, of unknown material. The old cables were rubber-insulated, had a circular cross section, which made it easy to keep their feedtroughs (left crankcase, timing cover) water/oil tight. With the irregular cross section of the Electrex cable version, it is not that easy. We applied an oil resistant putty to keep the oil inside and the water out - functional but ugly.
cheers Hans