H2W Jetting Matrix

Discussion in 'Dakar champion (950/990)' started by Head2Wind, Oct 9, 2007.

  1. wsmc99

    wsmc99 Been here awhile

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    570
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    I have not had any hot start problems with mine and the set up is per K2m's configuration.
    Pressure is a constant.
    #41
  2. cpmodem

    cpmodem Orange Caveman

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    Well here's hopin' you have a long dark winter :evil
    #42
  3. cpmodem

    cpmodem Orange Caveman

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    This thread just gets better and better. Bravo men for your hard work and long hours, and for keeping your "students" informed.:clap
    :bow
    #43
  4. Flanny

    Flanny Flanny-it-up!

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    So CMWoody...

    I'm intrigued...:norton

    I"m curious that the DNA filter alone requires one full step leaner Pilot Fuel Jet (42) versus your previous settings with DNA plus Uni Pre Filter (45) with the same needle position (3rd clip), and effectively the same Air Jet equation as accepted of 42/80/100??? (In fact I may remember that your idle circuit with DNA+UNI was 42/80/80 with the 45 Pilot Fuel and 3rd clip, which is richer still).

    Every fibre of my being says that the addition of the Uni (on either a DNA or stock paper) would enrichen the mixture (more restrictive) by both making fuel jets more responsive and reducing available air. So...Paper and/or DNA plus Uni would require leaning thing out relative to paper or DNA alone....

    Yet, you've gone to just the DNA and arrived at settings that are leaner that your previous settings with DNA+Paper (42 pilot versus 45 pilot).

    The only thing that has been enrichened is the main jets...Could there possibly be that much overlap on the increase in main jet size as to completely bugger-up conventioal wisdom on the idle circuit?

    Interesting indeed!
    #44
  5. Flanny

    Flanny Flanny-it-up!

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    Put the stock paper filter in tonight and went riding around with no right fuel tank on....:evil

    Set my needle at clip 3, IMS at 2 turns out and BINGO! F"ing perfect! 45 PFJ, 40/80/100 Air and 140/142 mains.

    This is reverting me back to the same set-up I has awhile ago according to my tuning notes, but which ran like crap -- I must have f'ed something up when I put it back together that time (like a carb vent or manifold or something). Damn!

    Anyway...while I was at it, I swaped Paper for DNA back to back both with Pre-filter. and did some short rides. At these settings the paper+uni combo is defintely more spot-on than the DNA+Uni combo. Very snappy throttle and good roll-on 2nd gear power wheelies. 1/8-1/4 cruise issues are resolved.

    With the DNA, I'd say the bike revs out faster, but the misture still seems lean throughout the range. I think going up one step on the mains to 142/145 (in this cold weather) would prolly make this set-up rip, along with tapering back on the air to 40/80/80.

    I'll let you know how it goes tomorrow...defintely a steo in the righ direction tonight!

    BTW - I also drilled the slides to 2.8mm, and that may also be contirbuting to the snappy trhottle as well...Cheers!
    #45
  6. cpmodem

    cpmodem Orange Caveman

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    :komet
    #46
  7. mgorman

    mgorman Crashing since 1964

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    Can anyone tell me if the fuel screw on the kein regulates Air or Fuel?
    #47
  8. cpmodem

    cpmodem Orange Caveman

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    Fuel
    #48
  9. K2m

    K2m Long timer

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    BINGO! F"ing perfect! :clap Flannys bike runs perfect with my jet setup........ good stuff
    #49
  10. mgorman

    mgorman Crashing since 1964

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    I was once told that if the screw is in front of the slide, it is a fuel meter, if it is behind the slide, it is an air meter. Has anyone else heard of this?
    #50
  11. K2m

    K2m Long timer

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    yes
    #51
  12. Flanny

    Flanny Flanny-it-up!

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    So I tried the DNA with one minor change on the idle circuit first. Richened up the mixture with a swap to 40/80/80 and now the bike runs like crap on the pilot circuit and idles rough. Doesn't rev out as quickly, and the pipe sounds really rough.

    I'm going to try leaning back out to 40/80/100, and then adjusting the fuel screw....or maybe I'll work back up to 90/100 to so how it reacts to that while maintaining fuel scre position at 1.75 and 2....
    #52
  13. tahoeacr

    tahoeacr Long timer

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    Can't help you with jetting since mine is FI. However, to make you feel better I hit the dyno and dna was worth over 2.5hp.
    #53
  14. K2m

    K2m Long timer

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    Just try a step or 2 on the mains Flanny. Leave the needle and pilot circuit the same as when it worked with paper. That should do the trick for the DNA.:freaky
    #54
  15. K2m

    K2m Long timer

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    Three totally different exhaust..........Three Paper filter with foam Pre-filter.......... Three "same jetting"........... Très fucking perfect:1drink :freaky








    Join us
    #55
  16. Flanny

    Flanny Flanny-it-up!

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    Actually on the paper filter with 40/80/100 and 140, 140 mains needle 3rd clip and fuel screws at 1.5 & 2 the thing is slightly rich across the range.

    I was out on Sunday and during the day at 22 DEg C. the bike ran rich...When the temperature dropped after dark, the bike came to life and ran almost flawlessly on the denser air...

    So...I think I'm going to jump up to 40/90/100 to see if that's enough across the board...
    #56
  17. K2m

    K2m Long timer

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    Flanny I think it will run richer with denser air. Which would suggest that it ran leaner across the range, but ran better when richer up in the denser air. I may be mistaken on this, but when you go up in altitude the air is less dense so it would run leaner correct?? Perhaps someone else could comment.

    We do not get to much altitude training in Oz:lol3
    #57
  18. cpmodem

    cpmodem Orange Caveman

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    All other things being the same, an increase in altitude will result in a richer mixture.
    #58
  19. cpmodem

    cpmodem Orange Caveman

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    Ha! You don't know the half of it. Runnin' around putin' out all these spot fires is wearin' me down, bro':knary
    #59
  20. K2m

    K2m Long timer

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    But this does not make sense.....................................:huh

    Denser air should be harder to draw through an air filter creating a higher vacuum in the venturi so sucking more fuel into the engine................I think:lol3

    I do love these discussions :ear
    #60