350 Sebring 6V to 12V conversion question

[Nick]

I've converted my Sebring to 12V by joining the two AC leads from the alt. and have hooked them to an old Honda rectifier. Coil, etc. also changed, the bike runs great. However, a voltmeter on the battery shows that it seems to overcharge (more than 15V) and it blows headlights (I run a sealed beam automotive unit). At present there is no regulator in the system and the rectifier is not grounded (I was told not to ground it with this set-up.) I've ditched most of the stock wiring except for the ignition key. Lights are run off a toggle via the stock hi/lo switch.
Question 1: Can I simply hook up a mighty mite electronic regulator/rectifier? If so, should I ground it, or not?

Q2: If wires of different gauge are used in my home-made loom, can that cause excessive loads that might blow a headlight?

Any info greatly appreciated. For anyone with a Sebring sitting around in the garage, I heartily recommend ditching the stock carb for a slightly larger bore Mikuni. My bike runs very well with this set-up, has 2 or 3 more HP, starts and idles well and gets 75 mpg.
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From probably the only person in the world who rides a Ducati 350 Sebring for daily transportation.

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You need a Zener diode. I used a Joe Lucas one from a Triumph when I did my conversion some years back. And by the way it was my daily transport despite bump staring being de rigeur until I found the right quadrant gear........

[Nick]

John, Thanks for the tip. I know I need a zener, but with my set-up, the rectifier isn't grounded. Also, when I converted to 12V, I simply joined the wires after they exit the alternator, without unsoldering them from the coils inside the alternator. Thus, this system works with an ungrounded rectifier.
Anyway, what I'm curious about is if it's OK to ground the zener? Or, would a grounded zener short circuit the system?
I've also got a Mity Mite regulator/rectifier which I'm going to try, and it, too, according to expert instructions, should not be grounded with my set-up.
By the way, a larger carb really brings the Sebring to life, mine runs very strong.

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Nick, a zener is like an overflow for the excess volts that are blowing your bulbs and will boil your battery too. It works by being connected to earth via a nut and thread which you must not overtighten. It also must be well heatsunk as it gets rid of the excess through heat. Think of it like an electric fire! I got the circuit for my bike, which required that the Ducati alternator was floated (the ground connection inside had to be removed from the rivet and the two wires soldered or connected together) from John Robinson at a magazine then called Motorcycle Mechanics in 1976 (?) I think it is now called Classic Mechanics so it could be worth contacting them to see if the info is still about rather than rely on my hazy recollections! All the best

John

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http://www.ducati-upnorth.com/forum/vbp ... =view&g=45

Taken late one night circa 1978... I think you'll guess which one is the Sebring!

[Nick]

Ho, Brah!
Love that intake manifold! It complements the angle of the rear seat so well.