KZ750L CDI

Hey guy's, new here, so hello all.

Here is my dilema, my CDI is missing on my newest project....a 750L.
I was rumaging through my stash of parts and found a CDI I saved. Problem is I cross referenced the #'s and its off a GPz550. GPz550 # 21119-1113, my L calls for a 21119-1050...anyone ever try a GPz550 box on the 750 or is the mapping different between these 2 parts ?

I may just bite the bullet and buy a Dyna 2000.

Thanks in advance for any info.

Barry

Just to be clear, both systems are not CDI. They are transistorized Kettering. They are often mis-labeled as CDI, but they are not. This is important in case you look for new coils. You should not use CDI coils. They will burn out the ignition.

The 85 gpz550 (ZX550A2) uses electronic advance. The 83 kz750L does not. It uses mechanical advance (according to the Kaw parts fiche). The two igniters are not interchangeable. The pickups and rotors are different inside the ignition cover. The igniters are very different as well.

In order to swap ignitions, you have to swap the entire system. That is pickups, rotors, and igniters, but even then I'm not sure the ZX550 advance curve will work well with the 750 motor. I suspect it will. It is not a digital map advance system. It's analog and rather basic. It has more total advance, but the advance is spread over the entire rev range whereas the mechanical advance is pretty much all-or-none and changes within the first few thousand RPMs or so.

You can find the igniters pretty cheap on ebay for the mechanical advance type. They are all basically the same. Or you can build one for about $40.
home.comcast.net/~loudgpz/GPZweb/Ignition/GPZgmHEImod.html

Thank you, more info than I was expecting...I like it here already.

A true CDI (capacitive discharge ignition) is quite different than the Kawi electronic ignition design. The kawi simply replaces the points (which connect the negative end of the coil primary to ground and then open to create a spark) with a solid state switch like a transistor device to ground. The pos end of the coil primary goes to +12V. Since the transistor will 'waste" some voltage drop across it, the kawi design uses a lower Ohm rated coil primary to get the primary current back up.

In a true CDI, the negative end of the coil primary is tied fixed to ground and the positive end of the primary is hit with a 400V pulse. The primary has no DC current flowing in it, just pulses when the ignition fires.

Was over at a friends this morning and he dug out a Dyna S ignition he had kicking around, listed for KZ550-650-750, he's into Z1's n' Z1R's. Boxed up in bubble wrap, it's used but in very nice condition, what should I offer him for it ?

Make sure it hase the rotor (which replaces the stock iron rotor) for the advancer. I'm not surre how much they are new. Like $100 to $150 new. Used, I'd say $50 to $75 on ebay.

Just so you know, Dyna specifies the coils must be 3-ohms or higher. That means you shouldn't use the factory electronic ignition coils. Some people have used them temporarily without any problems, though.

Also, you should know, the Dyna S uses a lot more current thatn the stock system because the dwell is extremely extended and fixed. This may cause some voltage loss in the fuses, switches, or wires. Keep an eye on the battery voltage while it's idling.

I dont recall seeing a rotor in the box, oh well. I may just get the Dyna 2000 complete kit, that way I'm not hunting for coils etc. Thanks again.