Data Logging for tuning your KZ

larrycavan wrote:

No, there are 3 simple circuits to tune. It's tuning the transition that's tricky. That applies to mechanical throttle slide carbs.

I agree with everything else you said, but what are you referring to directly, when you say "circuits". I was sort of contextualizing the word I think... meaning the different transitions.

Whaa?

seanbarney41 wrote:

man, that's kinda tough to figure without contextual information. I'm gonna have to take a wild stab and guess that you were cruising part throttle(just off idle) in 1st around 10mph, and then you ran it through the box going full throttle, shuttting it off when you shift. I bet you got going pretty fast in that 5 seconds or so, but it seems pretty good when you think about it. Goes real lean only when the throttle snaps shut. 13 to 1 at full throttle every gear? Hair bigger main? Lean out the pilot?:ohmy: :blush: :woohoo: This is fun. Can't wait to hear what others have to say.

Actually, that chart (I only looked briefly) looks to be similar to what I find. Closing the throttle, but seeing the RPMs stay up, I assume hes coasting in gear... that always leads to a very lean time (which is why that's when a lean bike starts popping through the exhaust). 16:1, in that condition (coasting in gear, throttle closed), is not unusual. I start to hear little pops and such when it gets into 17:1 or leaner.

Notice when he opens the throttle to 40-50% theres that AFR plummeting rich (close to 11:1), that's about what I find as well, but also notice it pulls out of that pretty quickly and gets back into 12 range.

Nice screen shot! I haven't really looked at it charted before, just studied my analog gauge in real time.

One thing I notice, that is different from my findings, is like around 2:25. Notice the throttle is closed, but the AFR gets richer as you slow down. And it seems to do that elsewhere as well. I wonder if that is an artifact of the CV that I don't see on my mechanical slide?

Allow me to provide the context. I had just pulled out from the gas station onto a 1/2 mile straight piece of road. I had accelerated up to about 70-75 mph. You can see that the gear changes from first to fourth are distinct. There is actually a upshift to fifth at 2:25, but I was unable to really get on the gas since I was approaching a red light. I think that the temporary rich condition is the effect of the mixture screws combined with the transition on to the pilots. It seemed that this was the condition that lead to the richest AFR's.

I didn't show the end of the log, but when I got home, the bike was idling at 12:1 and under after it was fully warm. Not sure where you got the idea that these are CV carbs. They are regular, mechanical slide, VM26ss carbs that are stock to a 1978 KZ1000A2.

testarossa wrote:

Not sure where you got the idea that these are CV carbs. They are regular, mechanical slide, VM26ss carbs that are stock to a 1978 KZ1000A2.

Yeah, I think I just assumed that. I'm not real familiar with the 1000's, and when I'm at work the photos and videos sometimes don't show up (blocked content).

Anyway, nice looking throttle position rig.

So it looks like you didn't get past about 50% throttle on that particular chart, is that correct?

I didn't get past 50% on that portion of the chart. I did have a couple of short full throttle bursts later one. I captured about 25 minutes of data on that particular run. I'll try and do another screen capture of the full throttle portions this evening.

Very cool stuff, Josh! Can't wait o see more.

On the screen capture you have a couple options.
1. The Print Screen key will capture the entire desktop not the cipboard which you can paste into Paint, Gimp, whatever.
2. Holding the Alt key when you hit Print Screen will capture only the active applications window in the same manner as #1.
3. Software like PrintKey2000 will allow you to select a rectangle (if I remember correctly) to capture to copy/paste, save, print, etc. www.webtree.ca/newlife/printkey_info.htm
4. Windows 7 has the Snipping Tool built-in which does the same as #3.

DoubleDub wrote:

2. Holding the Alt key when you hit Print Screen will capture only the active applications window in the same manner as #1.

I must try to remember that little tidbit.

testarossa wrote:

I didn't get past 50% on that portion of the chart. I did have a couple of short full throttle bursts later one. I captured about 25 minutes of data on that particular run. I'll try and do another screen capture of the full throttle portions this evening.

Good work,Tri.Now u can make a zillion bucks by going commercial with this and doing a "Super tune ur KZ" manual for dummies like me.Ride on,dude.bj

Sorry,didnt mean Tri,meant Testrossa.My bad.bj

It looks to me that as you begin to accellerate the engine you drop the throttle position. Your readings will be fairly meaningless if you don't have more control data (stable input). Find a nice area where you can use WOT, or half throttle whatever, and hold it there. You only need to flick the throttle to shift then slam it back open, or just power shift with the clutch. You will get much more linear results that are easier to understand and make changes to.

What your doing by slowly dropping the throttle in each gear as the bike accellerates harder, is mimicking a V-twin power band (trying to keep the torque pull the same feeling across the power band. go buy a v-twin :laugh: dont be afraid of the rush!

Not afraid of the rush. When I want that, I just take this one out for a spin:



That little snippet was in town, and I already hit twice the speed limit on that road during that little stretch. I agree that I need to get out on the highway where I can capture some steady state running data. I was limited for time when I recorded that. It generally takes me a good hour to get away from the urban sprawl of Houston to some good back roads. All in due time boys. As for V-twins, I wouldn't mind having one of those as well.

Yeah, that was my biggest problem too. Triple digits come up fast even just holding 1/2 throttle in top gear.

Early Sunday was about the only time I could do much testing.