Fuel screw working backwards??
  • SandySketch
    Posts:11
    Joined:Tue Mar 25, 2014 3:15 pm
    Fuel screw working backwards??

    by SandySketch » Sun May 17, 2015 11:13 pm

    My oem fuel screw has been working normal as of about two weeks ago. I put in a Flexjet and it works backwards, turning in where rpm should drop, it goes up. Turning out, idle lowers. Re-installed the oem and now it does the same thing. All parts are in the right order, double checked this. I just put in a new pilot jet a few weeks ago. I took the carb apart and cleaned everything and noticed the floating valve seal is missing, but it was missing before the problem started. Will be ordering one.

    I also installed an updated ac pump kit at the same time, Closely following instructions, and it wouldn't start at all, it would just try to start for second, never fully kick in. So, I switched everything back. That's when I noticed the problem. Checked and shimmed valves, one intake was off, still wouldn't start until I backed the fuel screw out an extra turn. Once warmed up, I tried to re-adjust and noticed the problem. Before I did all this, I just got my jetting right and was running great. Any ideas where to start.

    Thanks,
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    JimDirt
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    by JimDirt » Mon May 18, 2015 2:41 pm

    It can't physically work backwards is the issue , Open more turns is more fuel , closed in is leaner , its something else , you have a vacuum/air leak somewhere , or created a lean condition , the way to tell is to turn the fuel screw in ALL the way (but gently , do not force it once it bottoms out and lightly seats , then stop), if the bike does not die when you turn the screw all the way in , then you have a air leak , the idle will raise and lower , you should be turning it out and it will go higher , then start to go lower , same goes for turning in till closed , it will raise , then as you get close to closed it will drop until it dies

    The floating Valve Seal is a issue , and i don't know how you were getting a consistent idle with it missing the seal unless the plate was stuck to the slide or something , then once you removed it for inspection you broke that seal and caused your condition

    I am betting when you get the Floating Valve Seal , your issue will go away again
    2020 CRF450R
    2006 CRF450X
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    Weiser , Idaho
  • SandySketch
    Posts:11
    Joined:Tue Mar 25, 2014 3:15 pm

    by SandySketch » Mon May 18, 2015 7:02 pm

    I've never had a consistent idle, good one minute, high, then low. Some rides perfect the whole time. So, if it happens to not be the floating valve seal, what would be the procedure for finding the leak. Maybe I have a crack in the carb boot between the carb and motor somewhere, top cover and bowl gaskets. If I were to spray starter fluid around the boot and it affects the idle maybe, or would that be bad, not on the air filter side of course.
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    JimDirt
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    by JimDirt » Mon May 18, 2015 9:08 pm

    Here is what i suggest , replace the Needle Jet , its about $13 , when your in there , check the Needle itself for wear as well , it will have discoloration , what i am starting to think is your Needle Jet is worn out , causing lean , then normal conditions , this is a common but mostly overlooked issue

    The Needle Jet is the long brass tube that your Main jet screws into , and your Needle goes thru , this is usually a Dealer Item , so you can get it here , or at your local Honda Dealer

    It is part #27 (you did not mention what year your bike is , so i just posted up a 2006)
    http://partsfinder.onlinemicrofiche.com ... TOR%20ASSY.
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • SandySketch
    Posts:11
    Joined:Tue Mar 25, 2014 3:15 pm

    by SandySketch » Wed May 20, 2015 9:44 am

    I ordered the parts I haven't changed yet and a gasket/o ring kit. I think while correcting one issue, I disturbed things and created another. Parts should be here today and I'll see how it goes. Thanks for your input. And it is a 2006.
  • SandySketch
    Posts:11
    Joined:Tue Mar 25, 2014 3:15 pm

    by SandySketch » Thu May 21, 2015 1:52 pm

    Okay, I'm stumped. I carefully and neatly changed all jets, including Slow air jet, starter jet, needle jet holder, gasket/O ring kit, floating valve seal. O ring on new flex jet, wondering if the Flexjet might be made wrong. I don't know.

    Fuel screw does nothing turning in, or stays at high idle, and idle lowers when turned out at 3 turns. Hard to start now, cold or warm. Once it starts, it idles fine, it runs.

    It ran fine before, started first kick 98% of the time when warm. I just adjusted the oem fuel screw last time I rode and it worked like it was supposed to. All I did was put in the Flexjet and the updated ac pump kit, which I took back out thinking that was the problem, still out now.

    Out of ideas, not sure where to look from here.
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    JimDirt
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    by JimDirt » Thu May 21, 2015 7:02 pm

    What pump kit ??? , if its the pump cover with the adjustable Leak Jet , then put your stock pump cover back on , and the issue will be gone , that thing is a pain to tune correctly
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • SandySketch
    Posts:11
    Joined:Tue Mar 25, 2014 3:15 pm

    by SandySketch » Thu May 21, 2015 7:20 pm

    It's the pump kit from an 08 I think. Original Honda part. Shorter pin on the diaphragm and the check valve in the new cover for a stronger pump. I put it all back to stock 06 when this problem first started. CRF sells it, link below if it works. I thought that was the problem at first. I was told to pull the pilot jet and clean the hole with fishing line, spray it out and try again. Afraid to spray anything in the hole and cause damage to all the new o rings I just put in. Not sure if contact cleaner would work. I blew the orifices out, but didn't spray anything when I had it apart.

    http://crfsonly.com/howto/keihin-fcr-ca ... rf450r.php
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    JimDirt
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    by JimDirt » Thu May 21, 2015 9:07 pm

    Hmm well that should not have caused any issues with it
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho

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