electrics

[jhypnar]

I am restoring a 250 roadracer that I campaigned in the early 70's. Time to hook up the electrics. Here's what I have: 3 wire alternator, 2 spark plugs, 2 coils, wire from points, battery (?), kill switch.

Could one of you experts to tell me how to wire all this stuff together. I have some idea but looking for someone who really knows. Do I need both a battery and the alternator? HELP
Jon

[Jordan]

If you want an expert who really knows his stuff, you might have to pay for that.
Your ignition needs might be met by a simple total loss system.
That means just a charged battery feeding the HT coil and triggered by the points.
You can do away with the rotating weight of the external flywheel, and should work OK for short races, before the battery runs flat.
Search Kettering ignition diagrams for wiring connections.
It's one of many options.

[Nick]

If you're thinking of putting the bike on the street — or you simply want a modern system that generates its own juice reliably — check out this site:

http://www.electrexworld.co.uk/

[ducwiz]

Seems you have no regulator-rectifier, so the alternator is useless.

Have you checked your HT coils for their nominal voltage? They must be 6Volt types, as their primary windings have to be connected in series. In turn, this requires a 12V battery. And if you are going to connect the alternator into your system, the standard Ducati R-R can't be used, as it is designed for 6Volt. You need a modified, non-standard R-R.

Afair, there are 6V dual spark ignition coils available, which will solve your problem.

Hans

[double diamond]

If you had it running in the ‘70’s with this electrical system then these components must have worked. Check the rating of your coils. I have a set of 3V coils that were intended for a twin plug arrangement with 6V system. Is this a narrowcase or widecase model? Is the “alternator” actually an alternator or ET system? Matt