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[Scalyback]

most companies that do a momentary on, also do a momentary off (usually with a different colour button.)



My suggestion is to route from the positive battery, up to the momentarily off (Push to off) switch, and back down to the points. As long as the switch does not get moisture corrosion over time, it should be ok.




your points would usually be connected to power, until you hold the button in causing the engine to stop. after that of course, with no battery, your system would be dead until starting again.

The only possible drawback is that the wiring and switch are one more thing in the ignition circuit that can potentially go wrong.



Flick your lights on or press either brake after stopping the engine if you want to play with the wiring, as sometimes the capacitor can store some power for a while, and can make you give a 'false smile' when playing with points and coil!

[Thack]

Count Johnny: That's lucky - it sounds like a good solution if the coil is so close to the handlebars.



Scalyback's suggestion will also work just fine, although as he says putting a switch in series with the coil is opening yourself up to a reliability risk unless the switch is waterproof and has sufficient current rating.



On that subject, make sure your switch is capable of carrying the necessary current. The coil on my UCE should be between 4 and 8 ohms. With a 12V supply that means it will carry 2 to 3 amps. Even though the current flows in pulses, rather than continuously, you would be wise to make sure the switch is rated at 3A.>br>


If you use my approach with your normally-open switch, an under-rated switch may weld the contacts together when you operate it, stopping the bike from starting again. If you use Scaly's approach with a normally closed switch, an under-rated switch may burn out the contacts and stop the engine from running.



In summary I'd recommend a normally-open switch, rated at at least 2A and preferably 3A, and use it to short the "points" terminal on the coil to ground.

[Thack]

Count Johnny, I've just noticed something that has puzzled me.



You wrote: "That's interesting and accords with my first idea of shorting the points by switching the positive coil terminal directly to ground." Did you make a typo when you wrote that? I thought the usual approach is to have the 12V feed from the alternator/rectifier going to the positive terminal, and the negative terminal then goes to the points. Is that how you've wired it?



If so, then connecting the positive terminal to ground is putting a dead short across the alternator/rectifier output, and not what you want. I was talking about shorting the points to ground, which you would do by connecting the coil's negative terminal to ground.



Have I explained that OK?

[Count Johnny]

Sorry Thack



I would appear to be bi-polar. I mean positive.

[Count Johnny]

Oh, FFS!! Negative. NEGATIVE!!



And I'm positive about that!

[Scalyback]

There is a small current through the points, the main draw in the inducted high voltage from the coil for the plug if I remember correctly.


Therefore, anything to do with current flow through the points would not need to be high current? Otherwise the points would always be burning out very quickly.



please correct me if wrong. !

[zippy]

If you were to use a momentary off switch, then it is alot simpler. Split your poins wire and extend your wires back to the switch. Press and hold until your engine stops. release to restart. No power draining shorts - no fire risk .

[Norm]

The most simple and easiest way is to just reach down and pull the plug wire off, will always get a laugh

[Scalyback]

See what we'de be missing if Norm had sold that inter???



Anyway, I'm still going for the push to cut switch in the points line. And zippy agrees! YAY!

[Leon Novello]

Another case of creating problems where none existed before; fixing things till they break. Usually the problem is starting the things, not stopping them.