Electronic Ignition for Lambretta / Vijai After fighting through various options I finally settled with a CDI setup of LML Vespa in my Vijai.
1) In principle a CDI / TCI unit would need a Zero crossing for the unit to initiate a spark. This is done by the pickup coil. To keep the cost down I had tried to convert a points flywheel to an electronic by creating a notch for triggering the LML pickup coil. Due to lack of time I ended up buying an electronic flywheel for Rs3500/- from Delhi. As this was sufficient to create a zero crossing, I connected a 2 stroke TVS rickshaw cdi and started kicking. The TCI was powered by a 12V battery. Unfortunately the TCI conked off after producing a few sparks and failed abruptly, and this TVS part was found no where in Pune. Every 3 wheeler shop had this part for Bajaj & Piaggio 3 wheelers only. Hence I had to think of plan B.
2) The second part of operating a CDI (dropped continuing with TCI) is it needs a source of 200 - 250V for charging a capacitor. So I bought a 12V to 220V 20W inverter circuit and powered an RX100 CDI unit. Triggering was by Vespa Pickup coil only as the stator setup was left as it is. This time there was only 1 spark as soon I power the CDI, but nothing else. Checking the voltages revealed that the capacitor needed a high level of inrush current for few moments to get charged, which the inverted was not able to produce. So again had to move to plan C
3) From my collections I pulled out an LML Vespa stator plate. Drilled out the rivets and separated the stator from the Aluminium plate. Did the same thing in my Vijai's stator plate. Used long 3mm Allan bolts + Nyloc nuts to fasten the LML stator on Vijai's Aluminium plate. I only removed the ground of lighting coils and soldered a long wire to bring it outside till a rectifier. Though I didn't have much hopes, I wired a RX 100 CDI and tried to see if I got any sparks. As expected it didn't. After checking at 4 shops, I was lucky to find a LML Vespa CDI unit itself. Downloaded some internet material to understand its wiring and did the connections. Viola, there were sparks from the Sparkplug. AT the moment I am using the Vijai Ignition coil & sparkplug with the Vespa CDI. It works fine. Drove it for 10 kms after experimenting for about 7 months. Feel like it needs a little advance in timing. But I was greatly relieved that I don't need to set the points anymore .
Attached pictures are of the Vespa CDI unit and Piaggio Ape Rectifier unit. And now I have a full DC electrical system and can bolt a battery anytime. |