60s and 70s Motobecane electrical differences

I am putting together a 60s mobylette. The engine is not worth working with, so I have decided to go with a 70's engine sporting a 60s head. (everything looks like it will work so far)

Allthough both are 6 volt systems, the 60's model has one fewer wire coming off the magnetto.

How can I deal with this?

Can I just hook up one of the 70s stator plate outputs to feed the whole 60s lighting system?

Thanks

-Dan Adams

Re: 60s and 70s Motobecane electrical differences

Geoff Hazelton /

Or use the 60's stator plate. Is one of the wires connected to the points (kill wire)? That problem should solve itself.

-Geoff

Re: 60s and 70s Motobecane electrical differences

That was my plan, But I have been unable to remove the flywheel nut.

I have tried all the tricks I know.

Re: 60s and 70s Motobecane electrical differences

what about some heat

Re: 60s and 70s Motobecane electrical differences

Dan,

I don't have a diagram for one of the 60's bikes, but I'll take a guess..

The 70's 6V systems use a zener diode, and I'm guessing that the 60's bikes do not. That's what the extra wire (black?) is about on the later magneto.

Can you confirm yes/no to a zener on the 60's bike?

Re: 60s and 70s Motobecane electrical differences

Mike Scouty McScoutington /

i had to take an angle grinder to a magneto nut when it was giving me a hard time. wrecked the nut, but got the stater off.

Re: 60s and 70s Motobecane electrical differences

Yeah, Ive done some crazy stuff to get those nuts off too.

But thats another post.

and I am not sure the 60s stator would fit on the 70s engine

It has no zenor diode.

If that is true, I can just hook up the 60s bike electronics to the "brown wire post" on the 70s engine.

Right????

Re: 60s and 70s Motobecane electrical differences

Mike Scouty McScoutington /

let me run it by my buddy nick today. he knows his electrical stuff. i will let you know as soon as i find out what he thinks

Re: 60s and 70s Motobecane electrical differences

Dan,

Problem is, that black wire is actually the tail end of the exciter coil. It's used to run the tail light on the 70's bikes (just tail, not break).

At a minimum, you'd have to ground the black wire.. but if that exciter coil also has a center tap, that would cause it to overheat and burn up.

If I get the chance, I'll take a look at my spare 70's 6V stator and see if it's practical to ground the black lead and run like that. But keep in mind, the lighting coil is only spec'd for running a headlamp and brake lamp.. you might need to keep the wattages down if you intend to run the tail off of it as well.

I hate Motobecane electrics.

Re: 60s and 70s Motobecane electrical differences

Thanks for the help.

Now that I have decided not to use the 60s engine, I can try using destcructive force to get the magnetto off, and see if it fits

Hey Legendre

any more thoughts on this? should I ground the black wire?

or could I use the black wire to run the tail light?

the amperage is a lot lighter with LEDs right?

suppose I was to use LEDs for tail, and brake lights, and run it all off the white wire? what do you think?

Re: Hey Legendre

Hey Dan, how have you been?

I totally zoned this out, I'll try to check that stator at work tomorrow. But from what I recall, it should be safe to ground the black wire.

You can't use the black wire to run the tail light, unless you install a stock zener diode into the system.

Yep, LEDs use much less current than incandescent lamps.

Re: Hey Legendre

Dan,

Meh, I'm getting old and starting to lose it I think.. Here is the diagram (which I made) of a 6V Moby magneto:

As you can see, no center tap on the exciter coil. You should be able to ground the black wire, and it should make sparks.

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