Misc: Ignition Idler

Simon Dinsdale

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A lot of bike manufacturers used tufnol when using an ATD but used a solid metal gear when using a manual timing mag, but not Vincent. I know Velocette used a steel gear on a manual mag so I doubt the weight of a steel gear would be an issue as I would guess its about the same weight as an ATD. Why tufnol for some and metal for others I don't know but it throws the electrical theory out the window.
Simon
 

Vincent Brake

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I have another bad gear for you, erik. Can that turn it down? Until it doesn't weigh anything anymore.
Greeting

Ich hab dir noch mal ein ungehartes zahnrad, erik.
Kann das mal runterdrehen.
Bis es nix mehr wiegt.

Gruss
 
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Chris Launders

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I always thought it was in case the magneto seized for some reason it would shed the teeth and not wreck anything, the same applies with the magdyno dynamo drive, strangely they all use steel mag drives, it's only ATDs that have fibre.

You should be able to machine enough away from a cam gear for it to be light enough not to be a problem.

Actually after consideration I wonder if it was so as not to load the mechanism of the ATD centre
 

bmetcalf

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The other steel pinions are supported on both sides, not overhung. Maybe PEI didn’t think mag bearings were up to it?
 

erik

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Zündapp ks 600 and 601 have tufnol gears on the camshaft because of the noise.Some cars had it ,too in the good old days.
@ Vincent: Gebongt, mache wir !
 

Pete Appleton

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You don't want to insulate the armature as you need a return path for the HT spark. It is true that the bearings sit in paper insulators but I assume that is to prevent erosion by current passing through them. The earth path is provided by the earth brush.
 
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