TOPIC:

loudhvx wrote:
There is a chance the blue wire on the new igniter is not connected to anything either. But they put it there just to make hookup faster in case someone with a Zr400 didn't want to read the diagram. Try ohming out the blue wire to every other wire on the igniter swapping the polarity of the meter leads. By that I mean ohm everything out twice. Once with the black meter lead on the blue wire, then once with the red meter lead on the blue wire. Hopefully it shows no continuity, or maybe direct continuity to ground or power. No continuity doesn't necessarily mean there is no connection, because it could go to a relay contact or something, but at least it gives a clue.

Good idea, though I'm not sure how to interpret the results. I'm getting resistance measures (if I swap around meter leads) between blue and all the other wires. Would it help to provide specific resistance numbers? I do get some different results if I swap the meter leads (e.g. if I put meter red to blue and meter black to red, I get no continuity (0.L reading on meter). Every other combination with meter red on blue gives a resistance value. On the other hand, with meter black to blue, I get resistance values for everything except I get 0.L readings for the Y and the Y/R wires.


Just to be clear, these are the wire colors I'm referring to.



These are the mappings of these wires to the zr550 six-pin connector (from an earlier post)
output connector || Uotani input
R (zr550/Br (zr400) - > R
BK/Y -> BK
G -> R/Y
B -> Y

I'm going to try to install the igniter tomorrow . I think I'll try it first with the blue lead unconnected as suggested.

Well, I can't really imagine what the wire would do then. Strange that it would have any connection since the bikes it's meant to go on seem to show no connection on their harnesses.

Well this is funny. I checked out the zr750 wiring diagram and I see two dead-end wires from the igniter, a grey one and a pink one! So mysterious.



I'm going to install the igniter with the blue wire unattached today.. We'll see. If that doesn't work I might try running a positive lead to it. Not sure why it would need it but that's the only thing that could be coming out of the ignition switch as far as I can tell. I don't see any grounded wires going in.

random thought - it seems like unattached wires coming from electronics are usually antennae. I can't imagine any use for antennae in an igniter, but maybe it's to help dissipate electronic noise or for calibration or something crazy like that? I mean it's doubly weird that the zr750 would have two of them...

Yes, but then why go to the ignition switch? It is a good puzzle.
Maybe it's like what map-makers do... intentionally draw mistakes into their maps so if someone else publishes the same mistake, they know it was copied from their map, rather than drawn from actual cartographic research.

Well looks like the ignition is working fine without the blue wire. Just took the bike for a spin. Start-up was ridiculously easy - a split second on the switch. Haven't noticed any change in power, though everything is super-smooth. Looking forward to playing with the different curves. Thanks for your help, Lou!

That's great!
Have you played with the plug gaps yet? As long as the coils and igniter are designed to handle that, you should notice at least a small difference.

The blue wire makes me want to buy one and cut it open to see what the heck it's for.

loudhvx wrote: That's great!
Have you played with the plug gaps yet? As long as the coils and igniter are designed to handle that, you should notice at least a small difference.

Yes, they recommended setting the gap at 1.1-1.3mm (stock is 0.6-0.7mm). I set it at 1.2mm. Went for a nice ride just now. Start-up is comically easy. I don't know if there's really more power but it feels peppier and for lack of a better word, "thicker" throughout the rev range. Not sure how else to describe it. It's beefier. I played a bit with the advance curves and was surprised to find that the ideal setting seems to be at 0. If I advance or retard the ignition timing even 2 degrees it seems I lose a little power. Seems unlikely but there it is. I'll keep playing with it.

loudhvx wrote: The blue wire makes me want to buy one and cut it open to see what the heck it's for.

Lol, I'm super-curious too, but that would be an expensive experiment! I'll contact them directly and see if they have any further info.

Wow wow wow!!!! I take it back. I cranked up the advance 6 degrees and the bike just.wants.to.go.fast!! Holy crap. It’s like a freakin turbo. Changed the whole character of the ride. When not gunning it the bike is like a caged animal, kind of bucking/begging to go. Not smooth at all. But if I give her what she wants, man!
Also noticed popping on decel disappeared entirely.
I don’t think I’ll crank it up this high in the city, the bike is way too jumpy. But on these twisties
No pinging yet. Do I dare go to 8 degrees?

Well, just be careful. Many people experience the euphoria just before things blow up

I wonder how hard it would be to add a knock sensor somewhere.

I'm curious as to what the 6 deg value means. The stock advance is way more than 6 deg, so is it 6 more than stock? I wouldn't have thought 6 deg would have been that effective.

loudhvx wrote: Well, just be careful. Many people experience the euphoria just before things blow up

I wonder how hard it would be to add a knock sensor somewhere.

I'm curious as to what the 6 deg value means. The stock advance is way more than 6 deg, so is it 6 more than stock? I wouldn't have thought 6 deg would have been that effective.

Yikes. That's a scary thought. Now I need to research knock sensors. Though I'm thinking if something didn't blow during this past run, it should be fine. I was at or past redline many times.

I have the ignition curve at home, will post it when I get back. But yes, it's basically six degrees advanced over stock - all in at 43 degrees BTDC. I was hopeful that advance would help because I'm running the higher duration zx550 cams with stock 9.5:1 pistons. I'd read that one way to make up for lower dynamic compression is to add some advance. Don't know if that's what's happening, but something awfully fun is...

Here are the curves