Electronic Ignition

[Fairburn]

Rebuilding a 1958 LDA frame with 150 LD engine that has a Kanpur stator with white, red, green and brown wires. Harness was standard LD ie. coil, rectifier brake magneto etc. The electronic ignition is new. There is a Silver regulator 12v 80watt
Marked Taiwan Vespa co led and AC. The CDI unit is black with white red and two green outlets.
Because of the LDA frame having the bulge shaped battery cover I think that fitting a battery would be way to go.
What regulator would be appropriate to provide B plus DC outlet for battery. Should it have 5 outlets, should it be a DC regulator or is AC regulator / Rectifier the one to buy. I have seen Regulators with higher than 80 watts, are they suitable.
I have worked out that Brown wire from stator is the feed to the regulator.
Some regulators have a C terminal and diagrams show this as feeding out DC power to headset for lights etc.
Looking at harness I wonder if modification would be more problematic than swooping in an electronic harness.
Any advice on sourcing cdi, regulator and harness would be welcome
Any advice on adapted or replaced harness would also be helpful.
Thank you for reading.

[Steve J]

I'm not familiar with the Kanpur stator - sounds Indian to me, so is it one of the Scoot RS electronic conversions for the LD, using a six-pole stator & flywheel from a GP? Photos would be very useful.
(The original LDA Mk3 setup used a 4 pole Filso flywheel, larger coils on the stator to charge the battery and an electromagnetic regulator. It also had a 12V DC ignition system, so the cam driving the contact breaker had a different profile, keeping the contact points open for most of the time to minimise the current drawn by the ignition. It also produced just enough power for the 24 watt headlight....)
If yours is a system derived from a six pole GP electronic setup, then your easiest course of action would be to follow wiring diagrams used for electronic conversions on Series 3 and GP scooters - run all the lights on the regulated AC supply, with a trickle charge for the battery. Run a 12v DC horn and stoplight from the battery and the job's done.
If you wanted to be more ambitious, get a Wassel (or similar) full wave rectifier/regulator, and run everything from the battery. That would give you the chance to build the scooter as an updated LDA - provided you could find a starter motor and all the other bits needed.......

[jbcollier]

If you use the varitronic/vespatronic regulator, it has four terminals with 12vAC and 12vDC outputs. Really though, what do you need 80w and a battery for? The lights will be more than bright enough at idle so the battery is unnecessary. The only reason to have a battery is if you have electric start.

[Fairburn]

Would have preferred to work towards a full LDA scooter but the parts I need seem impossible to source. Will take advice re ignoring battery and running lights etc from Regulator.
Cannot add a photo of stator as timing is set and Flywheel is on. Going round from bottom in stator there is black box with red wire attached. Then four wound coils with brown wire attached to the fourth one and then a cloth wrapped coil to finish the trip round. This has Green wire attached. White is to earth.
I am particularly interested in how to most simply adapt a standard LD harness to accommodate CDI, Regulator and tidy up none needed extra wires. This must be a common problem when adapting LD's to Electronic.

[jbcollier]

Hook the brown stator power feed wire to the regulator. Make sure the regulator is grounded to both the chassis and the engine. Hook up the harness power wire (typically brown) to the regulator AC out. That's it.

[Fairburn]

Thanks for the advice. I have now sorted the system out in my head. I bought an AC harness and the only part of it I cannot use is a dark green wire with ring attached that would have been for coil. I removed the wire from the loom. The position of CDI and Regulator is on a plate attached above the rear wheel. Issues still to resolve are
1. How to link the 18 inch short harness from stator direct to Regulator and CDI or to use a junction box.
2. Related to that is how to route short offshoot from main harness carrying light green cut out wire going to CDI and twisted together brown wires going to Regulator for AC power output to rear brake and headset.
3. What type of cover or modification to normal cover (eg. Drill it out) could be used to allow magneto harness to exit magneto casing to prevent weather ingress.
Met with some problems using bought in fork plugs there may be more than one thread pattern eg fine v coarse.
Also bought NOS replacement speedo cable marked for Lambretta LD. On measuring this discovered that it was 9cms shorter than the one required for Mark 3. Have replaced it with NOS of correct length.