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FUEL SCREW QUESTION
  • ROBSCRF
    Posts:27
    Joined:Tue Jan 08, 2008 3:25 pm
    FUEL SCREW QUESTION

    by ROBSCRF » Tue Aug 05, 2008 4:06 pm

    Ikeep thinking that i seen somewhere on this site that
    when you turn your fuel screw all the way in that the bike engine will die,and if not that you need to go to a bigger main jet? well mine still runs with it turned all the way in ,also have a little backfire action some times.
    seems to do this only apon starting.just questioning
    whether i should try a bigger main.i currently have a 160 in it.plus all the popular mods listed on this site.
    any help/opinions would be appriciated.
    THANKS IN ADVANCE FOY YOUR SUPPORT
    ROB
  • ROBSCRF
    Posts:27
    Joined:Tue Jan 08, 2008 3:25 pm

    by ROBSCRF » Wed Aug 06, 2008 1:37 pm

    HELP?
    ANYONE.
    THANKS........ROB
  • Asmith
    Posts:14381
    Joined:Mon Apr 10, 2006 7:52 am

    by Asmith » Wed Aug 06, 2008 2:38 pm

    What bike?

    What year?

    What mods?

    What elevation?

    What is the full jetting set up?

    Which aftermarket fuel screw?
  • ROBSCRF
    Posts:27
    Joined:Tue Jan 08, 2008 3:25 pm

    FUEL SCREW QUESTION

    by ROBSCRF » Wed Aug 06, 2008 6:00 pm

    2007 CRF 250X
    Opened air box,baffel removed from exhaust,boysenen
    quickshot2 acc cover,backfire screen removed,crf's fuel screw,jd jetting-red needle 5\th position,160 main jet 42 pilot, fuel screw currently set at 2 turns out
    thanks for responding ~.
    hope you can help me with this info
    thanks...........Rob
    Elevation 0 thru 3000 ft.
  • ROBSCRF
    Posts:27
    Joined:Tue Jan 08, 2008 3:25 pm

    by ROBSCRF » Thu Aug 07, 2008 4:41 pm

    HELP?
  • ROBSCRF
    Posts:27
    Joined:Tue Jan 08, 2008 3:25 pm

    by ROBSCRF » Sat Aug 09, 2008 9:31 am

    AGENT SMITH-ARE YOU OUT THERE?
  • Asmith
    Posts:14381
    Joined:Mon Apr 10, 2006 7:52 am

    by Asmith » Sat Aug 09, 2008 9:43 am

    ROBSCRF wrote:AGENT SMITH-ARE YOU OUT THERE?


    I'm always in the Matrix...

    The jetting you are running sounds correct. The main might be slightly too large, but shouldn't be an issue. We ran a 158 main with a similar set up.

    The fuel screw doesn't always kill the engine. The Keihin FCR also has a starter jet that will provide fuel at idle.

    The fuel screw at 2 turns should be about right, give or take 1/4 turn.

    Have you disabled the smog pump yet? You will ALWAYS get some popping when that is still working.

    Fine adjusting the fuel screw should be done while giving the throttle some quick blips. You will hear when it's correct. There will be no hesitation with respect to the rpms climbing. When it's wrong, it will hesitate and fall before the rpms begin to climb.
  • ROBSCRF
    Posts:27
    Joined:Tue Jan 08, 2008 3:25 pm

    by ROBSCRF » Sat Aug 09, 2008 10:45 am

    Yes i have removed the smog equipment.
    i was at one time running the 158 main,and then changed over to the 160,maybe i should have left it alone.
    thanks a million for your responce/advice,you have been a great help with getting my bike running right.

    ROB
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