Tuning The Advance Curve/Spring Rate...

otakar wrote:

Hay Lou, you should see if you can incorporate an electronic advance into your GM ignition system. That would be fantastic. Do you think that the older stile (pre 1984) pulsing coils would be interchangeable with the newer stile pulsing coils? Meaning, that just a more modern IC igniter with electronic advance, could be used with the older pulsing coils?

I've been working on it, but testing for that requires a lot more equipment. Most likely the pickups will work, but the rotor slug will have to be completely re-engineered. The progress has been slow mostly due to not having time.

I don't think the newer pickups could be replaced by the older pickups. The design is slightly different. But a rotor might be able to be made that would behave similarly. However, if it was possible, why did Kawasaki not do it? The big advanctage of the newer system is the larger radius rotor. That gives a much stronger signal.

My first goal is to make a box for the newer pickup/rotor, then see how feasible it is to get a similar box for the older pickups.

Here's a little of what I've had to do so far.
home.comcast.net/~loudgpz/IgnitionTestRigB/TempTestRig.html


I even went so far as to write a dozen programs to plot curves to emulate. Here's a screen shot from one, but I will probably not use any of them.

otakar wrote:

This is interesting, but seems a little odd. If that's the advance curve for the electronic advance, why use electronic advance? That's virtually the same as a mechanical advance. It also doesn't agree with most programmable advance schemes I've looked at. They almost always have a very gradual advance from about 3000rpm or 4000rpm up to redline. (I say programmable because they can be made to any curve you want, and so they would select the more ideal ones. The Kaw electronic advance is based on the reluctor shape which is probably simplified for manufacturing purposes, and maybe not perfectly ideal.)

Is there a chance that this advance chart is actually the one for the mechanical advance? (The manuals are notoriously bad on info like this.)

However, if the mechanical advance and electronic advance are indeed the same, then that would explain this question:
otakar wrote:

Also, did anyone ever notice that until the very end in 2005, the police bikes kept the original stile IC ignition with the original pulsing coils and mechanical advance? Can anyone TRY and explain that?

loudhvx wrote:

otakar wrote:

This is interesting, but seems a little odd. If that's the advance curve for the electronic advance, why use electronic advance? That's virtually the same as a mechanical advance. It also doesn't agree with most programmable advance schemes I've looked at. They almost always have a very gradual advance from about 3000rpm or 4000rpm up to redline. (I say programmable because they can be made to any curve you want, and so they would select the more ideal ones. The Kaw electronic advance is based on the reluctor shape which is probably simplified for manufacturing purposes, and maybe not perfectly ideal.)

Is there a chance that this advance chart is actually the one for the mechanical advance? (The manuals are notoriously bad on info like this.)

However, if the mechanical advance and electronic advance are indeed the same, then that would explain this question:
otakar wrote:

Also, did anyone ever notice that until the very end in 2005, the police bikes kept the original stile IC ignition with the original pulsing coils and mechanical advance? Can anyone TRY and explain that?

Kept the police bike mechanics from being out of work?bj

If you will notice in the pictures it shows the rotor is the one for the electronic advancer and the specs came out of the 83-85 supplement manual. The advance curve for the mechanical advance is a bit different. Here is the one for the. 81-82 bikes.

otakar wrote:

If you will notice in the pictures it shows the rotor is the one for the electronic advancer and the specs came out of the 83-85 supplement manual. The advance curve for the mechanical advance is a bit different. Here is the one for the. 81-82 bikes.

Yeah, I see that. They are so similar I don't see why they would go to a totally different system. I wondered if the wrong diagram for the timing is shown in the manual for the electronic version. Has anyone actually plotted the advance using an external tach and timing light?

Taking the midpoints of the advance range.
10deg @ 1700, 25deg @ 2800, 40deg @ 3400 for the mechanical.
9.5deg @ 1550, 25deg @ 3000, 37deg @ 3425 for the electronic.

If it's correct, then I guess they just wanted to get rid of the advancer. It's probably cheaper to use electronic advance, and less maintenance too. Could also be the dwell is more favorable in the electronic version. I haven't measured that yet.

There is a variable dwell on the electronic unit. unlike in the mechanical one. Here is the page describing it.

As you know, to me, the dwell control is the mark of a good ignition. I wonder how much the dwell varies. The mechanical-advance electronic Kaw ignitions do incorporate some dwell control (about 100 deg to 120 deg). It's minimal, but enough to make a difference... in keeping the coils cooler at low speeds... and it's probably heat that kills coils in the long run under normal conditions.

I hope to get some time this summer to look at the electronic advance system closer (I only have a zx550 box right now). If I find a cheap box for the 1100 e-advance, I might grab it to verify that timing. I think the pickups are the same, and the rotor looks the same, but the tooth angle might be a different length.

Wheres that popcorn munching picture :laugh:

I think I started something...

You're in it for the duration plus 100 days. :laugh:

:laugh: :laugh: :laugh: :laugh: :laugh:

TeK9iNe wrote:

Wheres that popcorn munching picture :laugh:

I think I started something...

I can blame you then.

One thing to note, regarding your original post, is that the way Kawasaki specifies the advance curve allows for a huge range of advance for low-mid RPMs.

Notice on this timing diagram:


At 3000 RPM you can be at 25 deg or you can be at 38 deg. That's a lot of variability. Basically, you'll have to set the beginning and end points and hope the mid points land somewhere near what you want.

I would play with the existing springs first. What I've done in the past was tighten up the end loop on one end of each spring just a tad. That alone made a big difference on my 550's.

So far, I have used the tighten up slightly method, but it just aint right yet. I'm going to try and stretch one of them just slightly by inserting screw driver and twist method. :laugh: Then keep using a little stretch at a time, till it feels right.

I'm trying to get a little more advance earlier on, without causing sloppiness/ping with too much advance.

I will play with the initial timing as well, like puting it at about 8 degrees BTDC to offset the quick advance, and see what happens.

I'd be at it today, but I'm getting nice new sunburst orange w/crystal sparkle, sprayed on my tank and covers!

OK, so... how much advance can I have early?
Can I just throw in high octane and advance the @&%$ out of it right away? Whats advantage/dissadvantage???