electronic ignition... no spark

[firekdp]

ok so are you saying that I put a 1.5v DC battery across an AC output from the pickup ? ie put both the battery and the LED in parallel across the wed wire and white wire from the pickup yes ?

No, just test the led across the battery, if it doesn't work off that it won't work on a good pick up.
So you need a led that will work off 1.5v.

[johnny650]

sorry I misread your post and I cannot edit my post because there is no flippin editing time ffs

The LEDs are spec'd to work from as little as 1.9v to 2.2v I don't know what the output from the pickup should be ?
I know that once every revolution the flywheel magnet fingers create a positive pulse followed by a null then a negative pulse which triggers the thyristor to switch and discharge the voltage stored in the capacitor in the CDI but thats about it

[johnny650]

ok so are you saying that I put a 1.5v DC battery across an AC output from the pickup ? ie put both the battery and the LED in parallel across the wed wire and white wire from the pickup yes ?

No, just test the led across the battery, if it doesn't work off that it won't work on a good pick up.
So you need a led that will work off 1.5v.

gotcha

Thanks for the clarification about the Vespa pickup so thats a no go.
I have ordered a Chinese pickup which should arrive in a couple of days if I attach that externally to the mag housing and fit a metal trigger strip to the flywheel as per A Tambs setup then that should trigger the CDI shouldn't it . Its effectively the same thing I would have thought

[firekdp]

I know that once every revolution the flywheel magnet fingers create a positive pulse followed by a null then a negative pulse which triggers the thyristor to switch and discharge the voltage stored in the capacitor in the CDI but thats about it

The pick up produces several pos and neg pulses during a revolution, however it is only when both magnetic fingers are over the pick up, that a positive pulse is produced high enough to switch on the SCR.
For the led test, the led must be able to light off 1.5v as this is about the size of the pulse.

Yes the external pick up will be exactly the same thing.

[firekdp]

Effing editing is s**t on this forum!!
Yes the external pick up will be exactly the same thing as sold elsewhere.

[johnny650]

Effing editing is s**t on this forum!!
Yes the external pick up will be exactly the same thing as sold elsewhere.

you said it bro

thanks for your help with this . I have to understand everything which is a bit maddening but its the only way to troubleshoot things effectively. otherwise we just end up substituting until it fixes something or we run out of money forgot to say, the electronic loom you sent me is superb quality .....so refreshing be able to to buy something made in Britain for a change instead of the Far East

[firekdp]

forgot to say, the electronic loom you sent me is superb quality .....so refreshing be able to to buy something made in Britain for a change instead of the Far East

Thanks very much. yeah it's a shame that more isn't made here but virtually all the latest electrical/ignition parts are straight out of the Chinese scooter/atv market and are so cheap that dealers can sell them at a "good" price and still make a tidy profit.

Back to your ignition. To discount any problems with the earth path, try connecting the yellow CDI wire direct to the plug body.
And when you do get a spark don't expect it to be as fat as a points system because CDI system sparks are of a much shorter duration compared to inductive ignition.

[johnny650]

just as well you said that because I was expecting a stronger spark from a CDI than points.
Good idea about the earthing. I often recommend that folk use a jump lead to create a perfect earth between the battery and transmission ...its a useful diagnostic.
I;m going to rig up a spare spark plug on the frame leg with a good earth so that I can use it to test for a spark

[johnny650]

well the new K2 pickup arrived today and I fitted it to one of the stators and tested it . Still no spark from either new CDI .
Low tension coil output tests fine confirmed by multimeter 1.5v AC and red LED flashes


The output from the new pickup is only about 0.5 AC ie 500mv is that what it should be ?

Tried both CDIs and several plug and HT lead combos but no buddy spark !

The flywheel is a brand new mid weight AF Rayspeed flywheel so should be a good quality but what could possibly be wrong with that ?

[johnny650]

I noticed this today and thought it couldn't be right.
The laminated fingers that support the pickup on one of my new stators has spread ? It looks like it has tilted the pickup face back from vertical . This could be causing one of the 2x pickup strips to be too far away from the flywheel fingers .

I bent the laminations back until they were horizontal before fitting the new K2 pickup and now it is at a 90 degree angle to the stator as it should be.
http://i130.photobucket.com/albums/p261 ... obqhlw.jpg
http://s130.photobucket.com/user/peanut ... w.jpg.html