2. CRF's Only Forums
  3. Bike Mechanics
  4. Jetting
  5. fuel screw question
Post Reply
Topic tools
6 posts Page 1 of 1
fuel screw question
  • xridgerider
    Posts:58
    Joined:Mon Feb 19, 2007 8:09 pm
    fuel screw question

    by xridgerider » Sat Feb 23, 2008 2:50 pm

    Just curious how often people have lost their aftermarket one and if you have suggestions on how to NOT let it vibrate out. I bought the Kouba CRF's only one. But I am a little hesitant to install it. I have heard a lot of people losing them. Also heard to stretch the spring out a little to help it. Any advice would be great. Thanks
  • Asmith
    Posts:14381
    Joined:Mon Apr 10, 2006 7:52 am

    by Asmith » Sat Feb 23, 2008 3:17 pm

    I have never heard of anyone losing a Kouba fuel screw, most lose the lousy aluminum ones.

    Make sure it's not backed out more than 2 1/2 turns. If it is, change the pilot to the next larger size and start the fuel screw at 1 1/4 turns.

    Some of the racers will adjust the fuel screw, then put a dab of silicone sealant on it. It will still allow you to move it when needed but will provide resistance to it vibrating out.
  • xridgerider
    Posts:58
    Joined:Mon Feb 19, 2007 8:09 pm

    by xridgerider » Sun Feb 24, 2008 12:54 am

    It is the brass one that I have. Thanks AS! I will give that a shot.
  • xridgerider
    Posts:58
    Joined:Mon Feb 19, 2007 8:09 pm

    by xridgerider » Wed Feb 27, 2008 8:24 am

    Hey AS, so I installed the fuel screw, but got another question. When I install the screw do I rotate it until it is completely seated and can't turn it any more? then back it out for my jet precision! I started it and it got tighter to turn so I stopped and backed it out alittle. Whats the procedure? Your help is appreciated. Thanks!
  • Asmith
    Posts:14381
    Joined:Mon Apr 10, 2006 7:52 am

    by Asmith » Wed Feb 27, 2008 8:28 am

    xridgerider wrote:Hey AS, so I installed the fuel screw, but got another question. When I install the screw do I rotate it until it is completely seated and can't turn it any more? then back it out for my jet precision! I started it and it got tighter to turn so I stopped and backed it out alittle. Whats the procedure? Your help is appreciated. Thanks!


    Make sure that it is not cross threaded. It should thread easily for 5 or 6 full turns.

    Once you are sure it's not cross threaded, screw down all the way.

    Then back it off the required number of turns for adjustment.

    The CRF 250X with a 42 pilot jet should be around 2 turns out.
  • xridgerider
    Posts:58
    Joined:Mon Feb 19, 2007 8:09 pm

    by xridgerider » Wed Feb 27, 2008 1:53 pm

    Worked out perfectly. I also added a little silcone around the base of it. I have heard too many stories about fuel screws falling out, 50 miles into a ride. Norm Kouba makes nice products, I have met him before, he lives here in Idaho. Great guy. I suspect I will have good success with this. Thanks for the tips Agent. :D
Post Reply
Topic tools
6 posts Page 1 of 1

Who is online

Users browsing this forum: No registered users and 3 guests

  2. CRF's Only Forums
  3. Bike Mechanics
  4. Jetting
  5. fuel screw question
Jump to