KDXRIDER.NET

Hi, i picked up on ebay a 220 motor with no cdi...

so i was thinking about putting a double map cdi (two or more powerbands that you can choose) like in ktms or gas gas...

is a 97 kdx200 cdi the same of a kx 125? i'm doing an hybrid with a cr 125 so i don't need lights and ''road legal'' stuff..

thank you so much!

I don't think the KX cdi work.

Important to note, the KDX cdi has 2 maps. One for kips closed operation, one for kips open operation. Any replacement would need to match this.

thank you....are the 200 and 220s cdi/ignitions the same?

thanks!

Good question. I wish I knew the answer. I'd bet they'd be close enough to work fine.

juliend wrote:Important to note, the KDX cdi has 2 maps. One for kips closed operation, one for kips open operation. Any replacement would need to match this.

I have seen you post this info more than once...and I just HAVE to ask...How exactly does the CDI "know" when the kips valve is open..and when it is closed...considering there is no sensor or any other device wired to it that would tell it? Magic?

Preset mapping, kips opens around 6k thus cdi reads rpm knowing the
kips is open or should be and changes timing.

TWMOODY wrote:Preset mapping, kips opens around 6k thus cdi reads rpm knowing the
kips is open or should be and changes timing.

Yup!

Thank you so much, i will look on ebay for a stock cdi/ignition for a 220....so i guess i won't be wrong...!

thank you again

p.s. just to know....can i put a entire system (rotor/cdi/ignition) with the stock flywheel?

TWMOODY wrote:Preset mapping, kips opens around 6k thus cdi reads rpm knowing the
kips is open or should be and changes timing.

Thank you...that makes sense! I was just super curios as to how that bit of wizardy worked!

It really doesn't read anything....FYI. At XYZ rpm it does what it's been programmed to do. Programmed to match mechanically governed PV open RPM. The 200/220 are the same.

fuzzy wrote:It really doesn't read anything....FYI. At XYZ rpm it does what it's been programmed to do. Programmed to match mechanically governed PV open RPM. The 200/220 are the same.

Um...... May I ask how the cdi recognizes rpm then ?

Is it not reading or receiving a reference signal from the stator
interpreting that as rpm then adjusting timing based on that
current RPM reading ?

LOL, INDEED that is the case. It's not 'deciding' anything is what I meant.

Thank you everybody for the answers.....but i don't get how the cdi ''knows'' that the bike reached 6k rpms.....no sensors or no reading....so how?



Another question...is the voltage regulator necessary only on the models with lights and road legal stuff? just to know if i cannot buy that cause i don't need lights......(or is necessary to have all the electric syste okay?)


Thank you so much!

If the CDI made some timing change (other than when the main timing curve kicks in at 3600RPM) when the KIPS fully opens (I think I remember my '89 opening at 7000) then it does so because with more RPM is more voltage peaks of the sine wave from the stator coil. The CDI is analog though and not digital and so any change would be gradual, not sudden. In looking over all the wiring diagrams of the KDX that are posted on the internet I did find one that had an additional wire that went to the speedometer and neutral switch. My educated guess is that the timing is retarded when the neutral switch is engaged to lessen the probability of it idling too high. I highly doubt there is any timing change in sync with the KIPS.
If anyone is looking for a cheap replacement for the KDX CDI then send me a message.
http://www.dragonfly75.com/moto/KDXCDI.html