Carb reset to factory settings
  • 450x509
    Posts: 3
    Joined: Sat Apr 25, 2020 1:14 pm

    Carb reset to factory settings

    by 450x509 » Wed Apr 29, 2020 1:47 pm

    I recently had an issue with my 05 crf450x not wanting to idle while off choke so I narrowed that down to the pilot jet. Got in there and cleaned it out but made a bonehead mistake and did not count rotations on my fuel and air screws when i reassembled. Now of course I am having issues getting it started. I am looking for help regarding the settings. I am guessing there is a method to setting both all the way in a certain direction and then counting back from there to get to ideal settings.

    I can currently only get it started while holding the throttle at half open and then hitting the starter. I am just confused as to which way to go with the screws.

    Any help or links would be very much appreciated.

    Sincerely,

    Bonehead.
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    Re: Carb reset to factory settings

    by Aussiecrf230 » Wed Apr 29, 2020 4:53 pm

    Hi 450x509 and welcome to the site,
    We have all done bonehead things at one time or another so now you just have to fix it.

    I assume you know which is your fuel screw to adjust idle mixture and which is your idle speed screw.
    4 Stroke carbys don't have an air screw that is what a 2 stroke has in lieu of the idle mixture screw.

    Firstly,
    Are you sure you have a clean idle jet/pilot jet, same thing different name?
    And are you sure passage ways for the idle circuit are clean?
    There is no other issues you are aware of like stuck hot start?
    If that is the case and you have fresh fuel you just need to reset your screws till bike runs properly.

    Since every bike is different we start with basic settings and adjust.

    With the fuel screw/pilot screw gently seated (Clockwise), then unscrew say 2 turns.
    The idle speed screw undo until it is not moving the throttle plate then screw back in till it starts to move and go 2 turns.

    If it was jetted close before it should start.

    You will have to adjust the idle speed till it get to something like normal.
    Now try adjusting the fuel screw say a 1/4 of a turn at a time inwards to see when engine stumbles because getting lean.
    remember how may turns out this position is.
    Now from your 2 turn out position try unscrewing a 1/4 turn at a time till the engine hunts (Sounds like huge cam).
    Adjust screw to half way between lean and rich and you should be close enough.

    After a ride you may find you need to adjust say 1/4 of a turn either way to make it sweet.
    You will probably have to adjust your idle slightly too.

    Your fuel screw should end up between 1 and 3 turns out.

    Sorry it is a bit long winded but is actually quite simple.
    Hope that helps
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: Carb reset to factory settings

    by JimDirt » Wed Apr 29, 2020 5:22 pm

    To add to what Ray mentioned , which is a good way to figure out where it will run best ...... The factory setting for the initial starting point for the fuel screw is 1-1/4 turns out from lightly seated for your bike , as soon as the screw is resistant to movement , then do not go tighter , you will damage the screw if you force it tight , just lightly seated is good , then start turning out , as Ray mentioned , counting turns in 1/4 turn increments , 1-1/4 turns out will get you to start then adjust as Ray mentioned till it is stable

    As a future reference , you do not have to remove the float bowl to clean or replace the Pilot or Main Jet , that way you do not need to remove the fuel screw , you can simply undo the 17mm nut on the bottom center of the bowl , then loosen the carb clamps at front/rear of the carb and twist the carb so the bowl is facing the ignition cover (it will go to about a 45 degree angle , it will not lay flat sideways) , you can then use a long skinny thin flat blade screwdriver and remove the Pilot , (not sure if the 05 has a drain screw , the 06 does , if it does you loosen it to drain the bowl before removing the nut to keep the gas spillage to a minimum)

    Drain screw is here in the red circle:
    Image
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • 450x509
    Posts: 3
    Joined: Sat Apr 25, 2020 1:14 pm

    Re: Carb reset to factory settings

    by 450x509 » Thu Apr 30, 2020 10:18 am

    Since every bike is different we start with basic settings and adjust.

    With the fuel screw/pilot screw gently seated (Clockwise), then unscrew say 2 turns.
    The idle speed screw undo until it is not moving the throttle plate then screw back in till it starts to move and go 2 turns.
    This is just what I needed - Very much appreciated!
    As a future reference , you do not have to remove the float bowl to clean or replace the Pilot or Main Jet , that way you do not need to remove the fuel screw , you can simply undo the 17mm nut on the bottom center of the bowl , then loosen the carb clamps at front/rear of the carb and twist the carb so the bowl is facing the ignition cover (it will go to about a 45 degree angle , it will not lay flat sideways) , you can then use a long skinny thin flat blade screwdriver and remove the Pilot , (not sure if the 05 has a drain screw , the 06 does , if it does you loosen it to drain the bowl before removing the nut to keep the gas spillage to a minimum)
    Great to know for next time! That carb was a PIA to remove and re-insert haha.


    Thanks guys. :)
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: Carb reset to factory settings

    by JimDirt » Thu Apr 30, 2020 11:27 am

    Yea , it requires lifting of the subframe , disconnecting the throttle cables , hot start , and TPS , and squeezing it out , and its still a pain ... OR , you can just loosen it , tilt it , and be on your way in no time :-k ;)

    Let us know how it is running after you get it set 8-[
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • 450x509
    Posts: 3
    Joined: Sat Apr 25, 2020 1:14 pm

    Re: Carb reset to factory settings

    by 450x509 » Fri May 01, 2020 10:30 am

    She's running great now. Fires right up and idles perfect. Thanks again!
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    Re: Carb reset to factory settings

    by Aussiecrf230 » Fri May 01, 2020 6:19 pm

    No problems glad to here.
    Might be worth recording how many turns out you ended up with on the fuel screw.
    Give you a starting point in the future.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas

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