Down under, an idiot and a 400F

Neevo, I got a NOS harness with my bike, I'd be happy to ship ya the original harness if that would help

I think I should be good, I'm quite happy cutting up the stock harness as the wires seem good but not much else is.

I was weighing up keeping it in case I sold the bike, but to be honest the bike is so different from stock now there is no point.

If I bugger it up though I may hit you up for it

PJ any advice on a good float height for my needs?

1~2mm above stock.
The fact you have adjustable needles helps a lot (even though they are a real PITA to adjust)
I haven't done a big bore 400 for such a long time I've forgotten most of the stuff (my brother threw out all my notebooks a few years ago)

crazypj said:

1~2mm above stock.
The fact you have adjustable needles helps a lot (even though they are a real PITA to adjust)
I haven't done a big bore 400 for such a long time I've forgotten most of the stuff (my brother threw out all my notebooks a few years ago)

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Yeah getting those needles out sucks big ones! So if stock is 24mm are you suggesting 25-26 or 22-23?

I have a good understanding of the jets and how they work but not sure on the relationship the float height plays. Can someone educate me?

25~26mm.
Higher you set float level, the lower fuel will be in bowl which changes all the lower throttle opening fuel delivery. (lean's it out)
Doesn't really affect max rpm operation as you will be jetting that separately (which then re-affects mid-range which means needle position)
You can spend an unreal amount of time road testing, it's why I think 'rolling road' (dyno run) with EGA is so great
Don't know pricing where you are but price has dropped dramatically in central Florida

Dyno isn't too bad here, I think about $300 all up. Might be worth it if I struggle to get it running perfectly.

neevo said:

Dyno isn't too bad here, I think about $300 all up. Might be worth it if I struggle to get it running perfectly.

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For that price you should look into an LM-2 kit. I'm getting the full setup this spring when I sell the KZ550. No more guesswork!

http://www.google.com/search?q=LM-2+wideband&aq=f&oq=LM-2+wideband&sourceid=chrome&ie=UTF-8#q=LM-2+wideband&hl=en&tbo=u&source=univ&tbm=shop&sa=X&ei=wVj9ULboLYrQqwHpzYB4&ved=0CFUQsxg&bav=on.2,or.r_gc.r_pw.r_qf.&bvm=bv.41248874,d.aWM&fp=c7e682ab8bcf7c59&biw=1920&bih=955

Yep, if it's data logger or can be connected to computer, that would make more sense than paying $300.00 for dyno tune as you can use it on all your vehicles

crazypj said:

Yep, if it's data logger or can be connected to computer, that would make more sense than paying $300.00 for dyno tune as you can use it on all your vehicles

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Yup, I ended up going with this. Should be here end of the week or next week early as I just got impatient.... I'll let you know if I like it. $189 shipped.

MotorbikeBruno said:

Yup, I ended up going with this. Should be here end of the week or next week early as I just got impatient.... I'll let you know if I like it. $189 shipped.

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HTF does it work?

I'm not totally sure on this, but you weld the 02 sensor into the exhaust pipes and those hook up to the data logger. From there you can see the A/F mixture at any given load and adjust your carbs to either lean out or richen the mixture. I think the ratio you want is 14.7:1, but don't hold me on it.

AFAIK, 14.7:1 is the stoichiometrically ideal ratio, but not necessarily where max power is developed; I think that's closer to 12.5:1. For the sensor to really tell you anything other than yes or no, it would need to be wide band.

Yeah you'd need a wideband sensor.
Ideal stoicheometric ratio is 14.7:1 meaning that to get complete burn and the most utilization of available power IN THEORY you want 14.7:1 air to fuel. But in the real world we dont see ideal so 14.1 ish is about right.
For max power in the real world you need to aim a little richer between 12.3-13.5 depending on your engine.

Im going to have to pick up one of these wideband O2 sensors. Would sure making tuning easy. "eh it feels rich" is not nearly as good as "oh im running 11.6:1 at 9000 rpm"

I failed to put the link in. sorry about that!

http://www.amazon.com/Zeitronix-Wideband-AFR-Meter-Logging/dp/B008466B14/ref=sr_1_1?s=automotive&ie=UTF8&qid=1358825887&sr=1-1&keywords=zeitronix

Sonicjk, that's exactly my thought. "it feels rich" doesn't cut it anymore. I'm tired of swapping sets and sets of jets based on OTHER people's engines. so this is hopefully going to help me. It should help me dial it in close enough to make it drivable AND zippy! I'll keep you updated Neevo, hopefully it works well and gives you a solution not only on this bike, but your next

MotorbikeBruno said:

Neevo, hopefully it works well and gives you a solution not only on this bike, but your next

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Thanks Bruno. Seems like a good solution to getting the jetting spot on. Can I confirm how you use it?

1. Weld in bung
2. Test each jetting phase individually (eg start on slow jet at idle)
3. Check ratio
4. Change jet based on lean/rich condition
5. Retest
6. Move on to next circuit (eg needle jet)

more or less, but you need to check fueling at different at different revs and throttle positions and then check transients

Yeah, it really needs to be tested under load. I was going to wire it in, make a "gauge pod" for it or some sort of mechanism to hold it on (not permanent...although you could if you wanted) then you do typical driving, and roll ons etc. Here's the main website. http://www.zeitronix.com/

Since you are asking. I should be able to see what a/f is at while at idle. That will let me know how the idle circuit is doing. (at a stand still, no need to "drive" the bike for this one) I'm not going to weld in the bung unless I am getting odd readings. The particular bike I am working on has 4-4 exhaust...so I can check each carburetor relatively easily. If it's a 4-1 you are checking all carbs as a whole, making it harder to diagnose which carb might be giving you problems.

Next up, will be a series of runs holding the RPM at different spots to see how the bike is reacting to certain RPMs, say 2000, 3000, 4000, 5000 just to get a bearing of where the A/F is at cruising speeds and mild attitude. (no changes to the carbs yet, just data acquisition) ----unless it's WAYYYYYY OFF.

Then it's finding A/F from 0-1/4 throttle, make sure it's not insanely rich/lean, then 1/4 to 1/2 and 3/4....and lastly WOT. Many times we have to compromise in other places and at WOT you are running REALLY rich or REALLY lean. I'm just tired of looking at plugs that look amazing, like toasted marshmellows.... without much carbon, and dont look lean...yet the bike has dips and funny spots here and there.

Now all of that....is going by reading hundreds of threads from car guys and a few bike guys since the info on doing A/F for motorcycles (especially carbureted ones) is hard as hell to find, I am choosing what I think will work. We'll find out! ;D

Good points Bruno. I tend to start with idle and make sure it's a touch rich. If it's 14.7 it will probably stumble as you roll on the throttle. A touch rich is like having a small accelerator pump and typically makes for better slow speed roll on.

Next, do a WOT roll on and watch the gauge or fit a TPS and log A:F and TPS position to an old laptop. See where the mains are at mid revs and top end and change main jets to get that right. If the slope is off, it can be tweaked later. If your dyno guy has a Factory eddy current system he can hold it at 500 rpm steps for you on the way up. If not, check teh data to see what's going on as the revs rise.

Without an A:F, you can use the one on teh dyno and check teh graphs. What you will probably see is lumpy at low revs as the throttle is wound open and then a gradual rise or fall in A:F ratio as revs rise. That gives you an indication of the fuel slope.

Then do a sweep at 1/4 throttle, 1/2 and 3/4 and again you want to see what the A:F looks like at different revs for a given throttle opening.

Without a dyno, but with an A:F gauge, get idle right and then focus on flat out WOT under load and glance at the gauge without fixating on it. Then repeat at 1/4, 1/2 and 3/4 throttle.

Next, just ride the bike normally and check the gauge at light load and cruising speeds.

Teazer and Bruno did a good explanation of how to set things up
Even when you get everything theoretically correct (according to gauges/monitoring devices) you may find on road driveability requires slightly richer or leaner mixtures depending on how fast you open throttle.
It may be easier to get as close as possible then modify you riding style (when in doubt, flat out ;D )
The other thing we always used to say (back in the day, but probably said even earlier)
"Change down, open up"