eBay Performance CDI's

[Yorkie]

Just spotted these on eBay:

http://www.ebay.co.uk/itm/111582879514?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Performance CDI's.

These are not mine.

Yorkie

[Drumnagorrach]

What do they do ?

[slob]

they're the CDI igniter units used on carbie Monsters (and SSs)
Strangely the DP ones were always a little cheaper than stock replacements
Handy to have spare if you own an older Monster

[Dirty]

they're the CDI igniter units used on carbie Monsters (and SSs)
Strangely the DP ones were always a little cheaper than stock replacements
Handy to have spare if you own an older Monster

Do these things (http://www.ca-cycleworks.com/2vcoils) do the same job?

[slob]

no, the cdi units provide the low voltage pulse which triggers the coils

the coils convert 12v into 20kv+

like these http://www.electrexworld.co.uk/acatalog/CD6901D.html

[Dirty]

Ah ok, I knew I had CDis but I'd never noticed I had coils too!

[Dookbob]

Just follow the plug leads back to the battery area and all will be revealed. If you are like me, a bit "old school " then think of it like this, the CDI units do what the points used to do, at least that's the way I have it figured.

[Dirty]

Ah yes, I understand points. So the CDis are essentially little electronic ignitions, one per cylinder...?

[slob]

Capacitor Discharge Iginition

a capacitor stores charge for a while (sort of like a mini battery) before dumping it,

more or less: a magnetic sensor (hall effect) on the crank (where your points used to be) tells the electronics where/how fast the crank is moving and the electronics around the capacitor vary the charge/discharge time to advance or retard the outbound pulse as required. the 12v pulse hits the low voltage side of the coil, which ramps in up to between 20kv and 40kv (depending on how much you spent) to fire the sparkplug on the high voltage side.

many systems use a single black box, ducati happened to use separate ones

[Dookbob]

That's exactly what I should have said.

[Darren69]

Do the DP ones have a difference advance curve more suited to tuned engines?

[Flip]

According to the Ducati Performance Accessories catalogue that came with my bike when it was bought new there are three listed as 'Variable Advance Control Units' 1.1, 2.4 and 3.0 all of which are only stated as being suitable for the 900.

Although the 'AL9000' marking in my catalogue is the same as on the one listed on eBay the one there is marked as being a '7.900 Release' and the chap selling it says he had them on a 600SS so presumably there was a Super Sport specific accessories catalogue that was given out to people who bought those models (anyone know this for fact?).

But yes, according to the (slightly dodgy translated) information in my book it says 1.1 improves output at low RPM, 2.4 improves output at high RPM and 3.0 is suitable for racing engines and high RPM.

http://i1372.photobucket.com/albums/ag329/fluke900/IMG_3485_zpsfjjtoxta.jpg (http://s1372.photobucket.com/user/fluke900/media/IMG_3485_zpsfjjtoxta.jpg.html)

http://i1372.photobucket.com/albums/ag329/fluke900/IMG_3486_zpseur82hv5.jpg (http://s1372.photobucket.com/user/fluke900/media/IMG_3486_zpseur82hv5.jpg.html)

http://i1372.photobucket.com/albums/ag329/fluke900/IMG_3487_zpsayy2hqsw.jpg (http://s1372.photobucket.com/user/fluke900/media/IMG_3487_zpsayy2hqsw.jpg.html)

[Dirty]

Great thread, just keeps on giving I've learnt loads thanks all :)

[Flip]

Does anyone know how the advance curves are altered inside those units as the ones on eBay look as though they are potted in red rubber rather than an epoxy which means if the standard ones are the same they could be dug out and altered to how you want them and then re-potted.

Has got me thinking- anyone got a knackered pair they want to donate?

[Dukedesmo]

Ignitech ignition module costs around the same, replaces both CDIs and is fully programmable.

Also has other programmable features; shift light, rev limiter, TPS input etc. For anyone who wants to 'tinker' it's got to be the way....

[Kato]

Essentially all those little boxes do is advance or retard the ignition, in an attempt to smooth it out

The 900 reacts much better to those small changes hence the reason they were marketed for 900 only, yes they will work as a CDI unit on a 600 but you will never notice and difference

The trick is knowing what the ignition curve is for the release that you have I believe they go all the way up to R 8.6