kawi needle info

[cchracer77]

Trying to break the oem needle code. Does anyone have info on the kawi NFTx and NALx needles?

[Jakobi]

Hows that?? From here: http://www.teamgreennews.ca/pdf/RS03-05e.pdf
I've saved a copy for later reading.

[cchracer77]

Thanks, I found that info as well. Worked out the calculations on the NALx and plotted it in my spreadsheet. The profile appears to start off like the N1Ex and NECx, but gets fatter from 1/3 on up. Still looking for info on the NFTx.

[swazi_matt]

What is it that you guys plot and what does it tell you? Trying to get a handle on jetting thx

[Jakobi]

Hey Matt,

Plotting is just in a spread sheet. If you measure each time the needle changes taper and then fill in the voids you get a respresentation of the needle graphically. You can then plot it against other needles to see how they compare at different throttle positions.

It helps if you're looking for a needle thats about the same as the stock one but without the epicly huge off idle richness.

[cchracer77]

Originally Posted by swazi_matt

What is it that you guys plot and what does it tell you? Trying to get a handle on jetting thx

Like jacobi said, think of tracing the needle taper in huge scale. The thicker the needle is at a given point the leaner it will be. Let's you line up several different needles over each other and compare them, see what the effects of clip position are, ect. It's sort of a rough estimate of the fueling from 1/4 - 3/4 throttle. Doesn't take into account other factor's though. You would need a much more sophisticated program like Simulink to accurately map the true fuel curve.

[GMP]

The JD spreadsheet does a decent job of incorporating the other circuits and estimating jetting overlap.

[cchracer77]

Guess I should have clarified more. Any spreadsheet based "program" is estimating total static jetting as a function of throttle position. That is, the orifice area of the pilot jet plus the orifice area of the main jet not governed by the needle. Looking at the PWK the needle is the part of interest in most cases, as the pilot sets the minimum orifice, pilot + main determines the maximum orifice, and the needle covers everything in between. To accurately see more detailed effects such as the slide cut, air bleed, ect requires the production of a 3+ dimensional fuel map based on very complex fluid dynamics equations, which cannot be modeled in a spreadsheet.

[swazi_matt]

is it possible to get the jd spreadsheet without buying the jets?

[pscook]

Originally Posted by swazi_matt

is it possible to get the jd spreadsheet without buying the jets?

I was just looking at it when I read this post.
http://www.jdjetting.com/xcart/home.php?cat=2

Only $20, I might spring for it after tomorrow. Looks very interesting.