New to me Neglected Kz1300B

StanG wrote: Cool. So, what's about the above numbers?

If you can tailor the total resistance to 2.7 ohms, that's the way to go. You can go up the the 3.0 ohms mark or slightly higher but then you start to loose the output voltage on the secondary side. Any lower than the 2.7 ohm range and you seriously take a chance of burning out the transistors CDI box.

When Trikebldr was here with us, he would adamantly insist on keeping the ballast (didn't matter the size) to act as a capacitor to mitigate the induced voltage coming from the secondary winding back on to the primary winding so that the transistors in the CDI box didn't have to stop that back voltage. Trikebldr had a great explanation going on about this entire ignition circuit and the pros and cons of changing out the ignition coils and I begged him to stay and finish his writing on the subject but he got pissed with some of the members over their slanderous attacks of his posts calling him a "know it all" The man was a genius and credentials to back up his thoughts. It was a great loss the day he decided to leave this site.

Me, I have dreams- I would really like to build a Megasquirt 3 a build it yourself DIY kit system megasquirt.info/products/diy-kits/ms3/ complete with sequential injection and coil on plug ignition, wideband O2 feedback with open loop firmware. This is where my heart is. The KZ is a guinea pig for me to experiment on and see where I can take it. I'm having a blast doing what I do when time permits. "Life" just keeps getting in the way. I'm up at 5 am and start making plans. By 7 am all my plans got tossed in the toilet and the rest of the day "just happens". Right now, I'm lucky to get 2 hours a week to work on the camshaft grinder tool build. (posting coming soon I hope)

Thank you Tacklehappy and Kawboy. A lot of info the the last two posts!
I read the thread by strate6 about the coil upgrade, and am also aware of the Nology and Ford coils upgrades as well. Certainly, sounds like a loss not having Trikebldr around. I am glad though he didn't pass away, as I first thought! I am slowly starting to see the picture and closer to deciding what I will do. I'd like to check the new NGK plug caps and the Beru silicone HT and compare them to the Kawasaki stock I have.

On the side note, lots of people do upgrades from a system like KZ to COP's (coils over plugs) on Yamaha Vmax. I did that as well, and the engine runs sharper and better in hot weather in traffic. There is no playing with ballast resistor. The stock coils are unplugged and removed - they come off with the power supply wires. New power wires are made with a soldered resistor in on wire to bring the resistance to the right number. Then the COP's are just plugged in into the system. Why can't be this done with doing the coil upgrade on Kawasaki? Mind you, I am not sure, but there probably must be a stock balance resistor left in place, because nothing gets removed. So, the small resistor added is after that and before COP's.

That Megasquirt 3 caught my attention. You are right. KZ1300 is a good bike to experiment on! I am dreaming of having another one one day and doing just that. Dream baby dream... haha

Ok so, all three coils ohm out to be 2.1. I assume that using the factory resistor which ohmed out to 2.5-2.9 depending on the post would be too much resistance? I understand that 2.1 ohm is not enough resistance and I risk damaging the ECU. So it looks like I need 3x .5 ohm resistors, one on each coil individually, yes?

My Kawasaki coils are 1.6, and Kawasaki resistors show 1.7. That's 3.3 total.
On the extreme what the manual says, if 1.2 - 1.9 is fine for coils, and resistors 1.5 - 1.9, then the safe totals show a safe bracket of 2.7 - 3.8.
SO, why people say the number should be 2.4 - 2.5 and NO resistor? 2.5 is below even the minimum 2.7 allowed by the manual.
My current coils/resistor OEM are total 3.3.
Kawboy installed 0.5 resistors with his 2.0 coils to get to 2.5.

It seems to me, that with my 2.2, 2.2 and 2.3 coils, I should be installing minimum 0.5 resistors, but even 0.8 would be fine falling withing the recommended range, making it 3 and 3.1.
I am leaning towards getting 0.5 resistors, but still pondering 0.4...... I don't understand the numbers people insist on - the magical 2.5, and I still can't get a simple straight forward answer. The 2.5 number is 0.2 below the extreme left recommended by the Kawasaki service manual.

So... If the common knowledge based on experience of people riding and maintaining these bikes says it should be 2.5 at best, that would be the number to look for.
The question is - if that's confirmed, why it can't be explained?

At this point, I am running tired of trying to get a scientific explanation to this. My choice will be getting 0.5 resistors to go with my 2.2 - 2.3 AW82 coils, and screw it if it blows CDI, CID, CIA, IBM or IRAyah

I replaced the original, now badly cracked coils on my 1979 A1 last year. I too was very confused initially about the resistance requirement and whether or not a ballast resistor was still required and with what specification of coil. I know from my experience in running old cars in the late 70’s that ballast resistors were used to enable cold start – when you engage the starter motor, the battery voltage drops and you get a weak spark. With a ballast resistor in series with the coil, it was very simple to bypass the ballast resistor every time the starter motor was switched on – hence better spark when starting.

My understanding, after a good deal of reading, is that our main issue is the Igniter unit designed by Kawasaki. This is effectively the simplest form of electronic ignition unit in that it is simply an electronic switch that replaces a conventional mechanical contact breaker or “points”. This electronic switch uses a “Darlington” transistor which is simply two transistors in a servo configuration which means that one transistor (imagine it as an electronic switch) is used to switch another transistor. This is like using a small switch to operate a bigger switch. This configuration enables the “switch” to handle more current and in turn to produce a higher voltage spark. Worth remembering that we get a spark when we turn the switch off and not on! It’s all about rate of change of current and it’s easier to get a very fast switch off than switch on.

Another approach to electronic ignition is the CDI or Capacitive Discharge Ignition. I won’t bore you with the details but this works completely differently to our units in that it charges up a capacitor to 300-400 volts via a transformer and then switches that charge through the coil to create a spark. If you want more info on the different systems, see what-when-how.com/automobile/electronic-ignition-automobile/

The issue we have with the Kawasaki 1300 igniter is that these Darlington transistors have a maximum current rating. If we try and flow too many amps through them, they will burn out. Kawasaki have not published the details for these transistors so we don’t know what their current limit is but, from what I understand, is likely to be around 5-6 amps. With the stock coils and ballast resistor, the ignitor will see about 4.5 amps (assuming a 14 Volt supply when engine running) which is within the transistor current limit. If we were to fit 2.2 ohm coils and no ballast resistor, the current flowing through the transistors would be about 6.5 amps which could end up overheating and damaging the transistors. As with all electronic components, exact specifications will vary and they will be given a “tolerance” value, so in some cases, maybe you can fit 2.2 ohm coils and run without any major issues. However, the Kawasaki manual states a minimum resistance for the combined coil and ballast resistor of 2.7 ohms – which is 5.2 amps at 14 volts. Most of us are therefore hesitant to go much above this figure. I fitted 2.2 ohm coils with 0.4 ohm ballast resistors which will drive 5.4 amps through my igniter and so far, this has worked great.

For more info on my experience and some pictures, see www.kz1300.com/index.php/forum/electrica...1300-how-to?start=78 and page 14.

For interest, my calculations for various options detailed below:

And a pic of my installed ballast resistors (after removal of the stock mounting brackets):
[attachment=5926]

Excellent write up. Thanks for that. I am currently lookong at getting some. 633 ohm resistors from autozone. With 2.1 coils that will bring me to 2.733 ohms. That sounds like the perfect config. So, for the yellow wire that i need to split to feed 3 ballasts now, can i just "split" the one wire into 3 separate yellow wires, looks like thats what you did in the picture. What kind of hardware did you use to split that wire into 3 individual wires. I don't much care tl just twist them all up and shrink tube it.