TOPIC:

Oh wait, is it the power from the kill switch circuit to the coils that I should be interrupting? I think makes more sense than what I was imagining.

The kill switch most likely powers the igniter and the coils. I am suggesting interrupting the branch that feeds the coils only. I think I would tap in right at the coils. On Kz's, that's an easy to access area. I'm not sure what the terrain looks like around the coils on the Zr.

You're right, looks like the power from the kill switch is connected to both ignition coils as well as to the igniter (red wire in the diagram).
But what other "power to the coils" is there? I see a green lead from the igniter to what looks like just the 3-2 coil (not the 1-4 coil). Then there's a black lead that connects to the just the 1-4 coil (but not the 3-2 coil), as well as to the tach. But shouldn't those then be grounds? I'm just trying to understand how the system works. I'm thinking the igniter is alternately opening and closing the circuits to the coils through the green and black wires. I don't see where the relay would fit in. Or is it that I would keep power (through the red wire) going to the igniter, but then connect the coils to that same power through the relay? So that would involve putting the relay right at that branch point where the coils are getting power from that same stop switch circuit that is feeding the igniter (but keeping power to the igniter in tact)?

Coils get power from a common source that stays on all the time as long as the ignition switch and kill switch are turned on. That is the positive side of the coils.

Each coil also has a negative side and that connection is either green or black, and those two wires are controlled by the igniter. Yes, they alternate between being open and shorted to ground through the igniter. (When they are open, they should read somewhere near 12v.)

The positive connection to each coil comes from the harness from some common point. Usually, that one common point is visible somewhere near the physical location of the coils. I am suggesting to break the circuit with the relay just before that common point. That will remove power from the coils just the same as opening the kill switch.

On your diagram, that common point would be just to the left of the two red lines going to the coils.

You would physically break (cut) that spot on the red wire and the two loose ends go to the relay.
On my diagram, those two loose ends are called something like "switched 12v power for coils" and "to positive side of both coils".

The igniter can stay powered on as that should not matter, thus it stays wired as is.

Finally installed the kickstand safety switch. Installation went pretty smoothly once I learned to properly test the diodes (using a multimeter). I fried a couple beforehand hooking them directly up to the battery. The switch is working beautifully, thanks again Lou!

That's great to hear. Nice job!
The difference between an experienced electronics tinkerer and a novice one is that the experienced one has blown up way more diodes.

loudhvx wrote: That's great to hear. Nice job!
The difference between an experienced electronics tinkerer and a novice one is that the experienced one has blown up way more diodes.

I have been there, also know as "Reverse Engineering".

Hi Zaddict - i have read this whole thread and am interested in your longer term update? Have there been any unforeseen issues or are you still totally wrapped with the results?

Reason for asking is - i have just finished re-building my 98 ZR550 from the ground up, everything except the engine which was still in good shape. As part of the build I dumped the old wiring harness (which was in bad shape) and re-did everything using a Motogadget M-unit as the heart and all new wires, which turned out looking great. Now the issue, basically no spark at the plugs!

I know that during the whole process i did have the coils and the ignitor wired incorrectly (now, as best i can tell i have them wired correct) so my guess is i have damaged one or both of these components. I have tested the coils, primary and secondary as per the procedure in my Haynes manual and they check out ok. I have scoured the internet and can not find any way to test the ignitor.

So the options i have as i see them, either start buying replacement parts one at a time until i find the faulty part, ending up with a new and very expensive stock ignition, or buy a whole new performance system. Given the rave review you have for the Uotani system i am tending towards this option.

Your (or others) thoughts on this would be most appreciated, plus if you have a diagram of how you ended up wiring the SPII wuold be great.

Thank you in advance...

I'm still very happy with the SPII. No problems at all. I noticed a bump in power, throttle response, and mileage. The rev limiter is great for missed shifts, and there's now a much shorter warm up period before I can ease back the choke.
Looks like they're on sale right now too. I'd check out some of the other reviews on Webike to help you decide.
Wiring was plug and play, with the exception of the (optional) kickstand safety switch that Lou designed. You'll want to make sure you have your wiring right before hooking up any new system. There might be enough info in this tread to determine that, comparing the wiring in the diagrams to your set up. Happy to help.

So today i placed the order for the full kit SPII and will await delivery from Japan to Australia, about a week. After studying all the pics and diags in the thread and using the M-Unit manual i have made this wiring diagram of what will happen when i plug the SPII into my bike.

For those not familiar with the M-Unit, it takes care of the key switch, kill switch and side stand switch inputs, all of which kill power to the Ignition wire. I would much appreciate any input from those in this thread more moto-electrically minded than me in case i have made a mistake.



Again, thank you in advance...

Only one pickup coil ?

His ZR550 ignition System need only one pickup coil to run.