CDI BOXES

[recracer]

I ordered A posh Box . Makes a world of difference as far as power goes . Does make it harder to start cold and won't idle below 2000 without stalling . So i thought i'd start a Thread on it ,To see if we can have Some colective knowledge about CDI Boxes . In searching myself i think theres alot of different part numbers with the same conectors and that the difference could just be the timing curve from one application to another . Have not found any published timing curves for any Box .

[forchetto]

The world of after-market CDI is fraught with danger and disappointment.

Lots of units from anonymous far East makers are virtually copies of the factory units and provide no gain. Just a placebo effect. Others just remove the rpm limiter allowing some benefit to be obtained from higher states of tune.

I've tried a few and found that some advance the timing curve so much that the vibration through the seat and pegs is unbearable and the engine pinks dangereously.

Xian Racing (UK) are the only shop that not only tries any new units out throroughly before releasing them on the market, but have close contacts with manufacturers to specify exactly the sort of ignition curve they want.

For example they now have in their "KAMIKAZE" range a CDI/igniter unit for the Qingqi QM200GY / Qlink XF200 Suzuki-derived bikes. This is unique as there was none on the market before.

I helped to develop them by getting Gareth to send me test prototypes and me fitting and trying them out.

They even have a unit that can be programmed at home using a PC. I haven't done any testing on that as I'm allergic to software....

This is the Qingqi/Qlink unit on my bike. Note that there's plenty of space around to carry the original as normal, so in effect you have two igniter units in case of trouble:



Xian Racing can be found at:

http://www.xianracer.com/temp/

This is their CDI page:

http://www.xianracer.com/temp/index....iewCat&catId=4

In case anyone thinks so, I have nothing to gain from this, except that Gareth has had the Qingqi unit made at my suggestion, and I got a free unit for my troubles, and the satisfaction of seeing it being marketed and available.

The reason why Gareth keeps sending me prototypes to test is not that I'm specially clever or anything, it's just that he knows I run a small stable of Chinese bikes and therefore don't get out a lot...

I have no means of doing any thorough testing, just feel of the pants and basic measurements as well as testing whatever units he sends me for reliability, ease of starting, durability, etc. They do however take the final prototype to a rolling road dyno to confirm the findings.

[recracer]

forchetto
i read your post on these and any other i could find . i see a posh cdi on that site ,not the one i have .i have the one thats all blue ,i think it's to far advanced at idle . even with it idling at 2000 rpm still has a intermittant missfire . if a little more was published on the timing curves ,we could pick and chose . in your testing ,did you try different plug gaps , jetting or did it all remain fine ?

[forchetto]

I know that Gareth has a lot of difficulty getting decent info, timing curves, etc from his manufacturers. They tend to be vague.

On the units I've tried I didn't try different plug gaps as the unit doesn't produce any higher voltage than the OEM one.

I did warn Gareth that my Qingqi and other bikes are already modified with such things as catalyser-less exhaust systems, less restrictive air filters, re-jetted carbs, Iridium plugs, higher gearing, etc and any performance improvements will not be too obvious.

There are so many variables that it's difficuly to reach any conclusions. For example I tend to use a higher octane fuel that is generally used around, 98 instead of 95.

For some of the tests I did go back to the lower octane to check for pre-ignition or pinking.

[Frog]

Hi

I posted on a POSH CDI on my GY5 200cc a while back.

Cheers

Frog

[recracer]

Hey frog i did read your post back then and looked like a promising cdi . however in my case not so much . i'll play with it again now that winters coming (time to tinker) Do you have any idea why it stalls out if i bring the idle down under 2000 rpms . could be there was not enough voltage ,had a charging problem then . bad stator would run ,but not enough power to keep the battery charged . are you still running that cdi with good results?

[Ma77]

I played around with the timing on my first bike (sachs madass) by removing the timing trigger on the flywheel and making a new one by welding and grinding to shape...also elongation the holes for the pick-up

advancing even a small amount made a noticable difference but if you really want more power best bet is larger capacity engnie really.

[Reveeen]

Probably more than you want to know about CDI boxes:

http://www.geocities.com/a57ngel/moto/CDI.html

modding to change the timing curve:

http://www.geocities.com/a57ngel/moto/CDI-mod.html

Lynn Edwards (a forum member here) has some schematics of Chinese CDI boxes:

http://s397.photobucket.com/albums/p...nt=5pinCDI.jpg

A "generic" 5 pin CDI (noting the value of C1 and how it relates to the above mod)

http://s397.photobucket.com/albums/p...0ccCDI6Pin.jpg

This one a 6 pin GY6 CDI (again noting the value of C1)

[recracer]

love that tech stuff Thanks

[Frog]

Originally Posted by recracer

Do you have any idea why it stalls out if i bring the idle down under 2000 rpms .

CDI is currently in my son's 125 and runs fine - no problem with stalling or in having a low(ISH) idle. I do not know why yours would stall out - has never been a problem with mine other than when I had an air leak on the inlet side.

Frog

[ohwow]

Is this the box you have?
http://s964.photobucket.com/albums/a...t=DSC00121.jpg
I gaped the spark plug to .075mm idles at 1800 now. gona try a performance coil eventualy[/img]

[recracer]

ohwow No mine is different ,it's a blue box with the connectors right on the box and no lable . just posh painted on . How do you like that one?

[Reveeen]

Is this the box you have?

I have one of those on my 125 (and one on the shelf destined for a 150cc). I had a high speed "flutter" that was a valve adjustment "issue", otherwise I idle just fine.

[ohwow]

Originally Posted by recracer

ohwow No mine is different ,it's a blue box with the connectors right on the box and no lable . just posh painted on . How do you like that one?

It's been ok noticable torque and revs higher, but i think i'm starting to experience the same problems as Reveeen. i've adjusted valves 2 times in a week.

[Reveeen]

And then:

You hit a product that might actually do something:

http://www.partsforscooters.com/Digi...ategory=74091#

NOTE: this box requires a separate source of 12V