cdi modules

Hi all, still sourcing and pondering how to modestly solve my cdi issue (namely sourcing a cheap suitable) finding a suitable replacement.
I think I've found one at least. Will post here once I'm sure it'll work.
Guess my question to others here is; is the cdi system on the kz250 ac or dc as I've recently learned there is a difference and one won't work on the other or at least not very well.
From what I've learned so far is normally if a rectifier is involved it's an ac system, if a battery is involved it a dc system.
Not entirely sure on his kz 250 if it has a rectifier or not.
Suggestions and comments welcome.
Thanks.

First of all, your bike doesn't have a CDI. The ignition is driven by an "ignitor", which is quite different from a CDI, which are typically used on dirt bikes.

Regarding rectifiers and AC or DC, that sounds like a charging system discussion.

What seems to be the problem here and do you have a factory Kawasaki manual?

Flyback ignitions, like on the KZ's do basically work on DC power, while CDI ignitions, classically, are powered by AC (though they can be powered by DC in more modern systems using inverters etc.)

The KZ250 ignition is unique among KZ's in that the rotor for the ignition is part of the alternator assembly. Usually, that is where you would find CDI-type ignition parts, but I think it's still, in fact, a transistorized flyback ignition with analog timing advance built into the module. That would be a tough module to find, I think, since it is used on very few bikes, and it incorporates timing advance in the electronics.

Regarding whether it's AC or DC, all alternators produce AC, and rectifiers convert it to DC. So most KZ's have both AC and DC, and rectifiers, and batteries. The way to determine if it's a CDI or transistorized flyback, is to test the voltage on the coils while in use.

Hi Nessism thanks for he kind reply, but unless I'm quite unlearned (which in some cases I am) I'm looking at a module that has IGNITION UNIT inscribed st the top, and below that has Type TID 11-01, and below that has Hitachi Lts. Tokyo Japan, below that numbers 1025, then 111. So unless I miss my guess it is a CDI module as I've learned online from other sources?
And from the previous individual who had his machine for a brief period noted here was no spark, they determined that his module was he cause. I've not tried to start or even turn he machine over as yet, taking the suggestion from this person (my stepson) that this is the culprit, also see in the inside of the module there seems to be a small cra k across the corner of the pcb.

Hi loudhvx, thanks for the reply and information I know very little about electronic ignition systems except what I see, hear and read about.
I'm not in the know about his particular bike either, as it a been said they're all different but in some ways the same. Please read the reply from Nessism, I replied to him about the CDI module and apparently the module seems to be an electronic ignition module and they are available but of course not cheap. Over $100. I think I may have found a source for quite a bit less which may work and even if it doesn't it's not a lot of mone invested, so gonna try that first.

Hi again Nessism, well upon a little closer investigation it seems so,e refer to this part as a CDI Module and others refer to it as an ignitor. OK you're right in particular but it seems one weblink refers to it as a cdi module so...either way it still relates to the ignition and spark.

CDI = Capacitive Discharge Ignition

The capacitive-discharge ignition uses capacitor discharge current output to fire the spark plugs.

KZ motorcycles use a the ignitor to charge the coils, which fire the plugs.

Two completely different types of ignition system. Yes, some people describe the ignitor as a CDI, but that doesn't make it one.

At any rate, sounds like you need a new ignitor and for that I'm sorry. They are hard to come by since that model bike didn't sell in large numbers. Not sure what to suggest other than to mention that some people build their own ignitions systems using parts like GM HEI modules. I know just enough to be dangerous in this regard so search around for info if you are handy with a soldering iron and want to give it a go.

CDI and transistorized flyback both use coils to produce the high tension voltage. CDI uses a capacitor to create a high voltage (but not high-tension voltage) pulse. This pulse is routed to the coil which steps up the high voltage (300v to 600v) to high tension voltage (30,000v to 60,000v).

The way to determine if it is CDI or not is to measure the voltage on the coil right before spark. Flyback ignitions, like used on most/all KZ's, will have 12v (approx) on the coil right before spark. CDI ignitions will have no voltage on the coil right before spark (because it is being accumulated in the capacitor).

Either way, it really doesn't matter what it actually is, or what it's called, because you will have to source the exact ignition module for that bike because the ignition timing depends on the ignition module. Your other option is a fully designed aftermarket ignition like a Dyna 2000 which has programmable timing advance. But that is way more expensive than the factory module. If you can get a factory module for $100, I would get it, assuming that is the actual problem.

hi and yeah someone did post a diagram using gm parts and HD a diagram n all for a 550 I can't find it now.