305 CDI voltage source

Several years back i wrecked this bike when some lady pulled out in front of me. I love the damn thing but have become so stuck i have contemplated giving it a viking funeral. After running through every little switch, checking every wire, and working on and off on this issue for the last year i have yet to find why i can not get the thing to spark. I just need a little guidance as i am not very good with electronic ignition. i know the coils work just fine but can't get a voltage to them. When tracing back it turns out i have zero volts at my CDI. I can't seem to locate on the wiring diagram where the CDI should be getting 12V from. I have found that all the wires going into the CDI from the harness circled in blue are grounded leaving only the wires going to the pickup coils, ignition coils, and diode left ( circled in yellow) . My assumption is that it must need to get 12V from the diode or it is shorting across one of the other wires circled in blue before reaching the CDI. Does anyone know which wire is used to expose the CDI to the 12V source on this diagram? i am assuming it exposes the ignition coils to a 12v source constantly and disconnects it to cause the spark correct? i also have 0V going to the diode but if that is what is supposed to supply voltage to the CDI i will at least have narrowed down the problem within the circuit.

Here's a link to the B1 in color which might help follow the wires, provided it's close enough to the B2 (which I haven't compared).

www.kzrider.com/filebase/category/46-kz305-electrical

Good Fortune!

Why do so many people call the ignitor a CDI?

Just thought I would reference it the same way as the Kawasaki manual. even if incorrect everyone calls them that. I knew i would catch some flack on here for it but it makes no sense to call it anything else when it's referenced as a CDI in most literature.

To answer your question I blame Kawasaki :lol:

I'll start by sayingI dont know anything about the 305 and I'm not great with electrics but I have had to patiently follw a circuit diagram to sort out issues on my 750.

So here goes in an attempt to answer the question " Does anyone know which wire is used to expose the CDI to the 12V source on this diagram?"

From the table labelled IGNITION SWITCH CONNECTIONS it appears that with the ignition in the ON position W (white) from the battery via the 20 amp fuse is connected to BR.
Following BR to the side stand switch and from there as G/W to the Diode I would think you should find 12V at G/W at the Diode if the side stand switch is operational and no breaks in the wire .
From the Diode to the CDI / Ignitor Im' thinking BR/W but this is just a guess.

That is a headache inducing wiring diagram.

Hope that helps

Thanks I will take another look at the side stand switch circuit. I agree with it being headache inducing ! :laugh: after staring at it for so long I thought I was going crazy, figured some fresh eyes may help.

punisher11b wrote: . . . coils work just fine but can't get a voltage to them. When tracing back it turns out i have zero volts at my CDI. I can't seem to locate on the wiring diagram where the CDI should be getting 12V from. I have found that all the wires going into the CDI from the harness circled in blue are grounded leaving only the wires going to the pickup coils, ignition coils, and diode left ( circled in yellow) . My assumption is that it must need to get 12V from the diode or it is shorting across one of the other wires circled in blue before reaching the CDI. Does anyone know which wire is used to expose the CDI to the 12V source on this diagram? i am assuming it exposes the ignition coils to a 12v source constantly and disconnects it to cause the spark correct? . . . .

Am not at all positive, but seems to me that W (among those circled in blue) from CDI is NOT grounded, but actually connects to BK/W from the ign switch.

And that Batt+ travels via BK/W from ign switch to W into CDI, and from CDI via R/BK and BK/W to ign coils.

Good Fortune!

Interesting about that CDI business.

The FSM for the following bikes calls the part an "IC Ignitor", without any reference to CDI, which makes sense because it's not a CDI:
KZ750 (4 cylinder)
KZ550
KZ1000
KZ650

Does the 305 use a different type of igintion system? The parts fishe calls the 305 ignition box an IC Ignitor.

Patton wrote: Am not at all positive, but seems to me that W (among those circled in blue) from CDI is NOT grounded, but actually connects to BK/W from the ign switch.

And that Batt+ travels via BK/W from ign switch to W into CDI, and from CDI via R/BK and BK/W to ign coils.

Good Fortune!

That did seem troubling as they are currently shorted to ground....the plot thickens. :silly:

Nessism wrote: Interesting about that CDI business.

The FSM for the following bikes calls the part an "IC Ignitor", without any reference to CDI, which makes sense because it's not a CDI:
KZ750 (4 cylinder)
KZ550
KZ1000
KZ650

Does the 305 use a different type of igintion system? The parts fishe calls the 305 ignition box an IC Ignitor.

i agree that it is very interesting. This has perplexed me for sometime since there is conflicting data on both sides. all i can say on the mater is when i went to buy a replacement they were listed as CDI and mentioned in the manual as such. i uploaded the "CDI" schematic . it appears to me that its a thyristor gate driven capacitive circuit. second year into an Electrical engineering minor and its way over my head :huh:

No eBay APP ID and/or Cert ID defined in Kunena configuration

punisher11b wrote:

Patton wrote: Am not at all positive, but seems to me that W (among those circled in blue) from CDI is NOT grounded, but actually connects to BK/W from the ign switch.

And that Batt+ travels via BK/W from ign switch to W into CDI, and from CDI via R/BK and BK/W to ign coils.

Good Fortune!

That did seem troubling as they are currently shorted to ground....the plot thickens. :silly:

Would assure Batt+ is getting through the connector from the ign switch and through the connector into the CDI.



I think the black dot represents a permanent connection between the W into CDI and BK/W from the ignition switch.

If the CDI is defective, could consider posting a KZr Wanted in Classifieds, and might conceivably be interested in one of these crap shoot possibilities ? ? ? ????



www.2040-parts.com/1987-1988-kawasaki-kz...known-good-i1096074/

Good Fortune!

i did try replacing the CDI with a supposed working one.... crap shoot as you said though. im starting to think that there is something in the wiring between the two. with the CDI disconnected those pins are still tied to ground. when testing the ignition switch per the FSM it did check out, im starting to think a second look may be required though.