Idle Screw Problem

5 replies to this topic
  • freestyle250

Posted April 15, 2006 - 01:26 PM


So I just got done messing around with the jetting on my '05 and got it almost where I want it. Except, this last time I rejetted, after putting it all back together, the Idle screw is having some issues. It only turns about 1/2 turn but its turning the whole sleeve, not just the cable inside. Im not quite sure what the problem is, But its very frustrating cuz the idle is a bit off. When i turn the knob, it almost feels like it has spring tension keeping it from turning all the way. its driving me nuts. :thumbsup:

  • dl19

Posted April 15, 2006 - 02:38 PM


Not sure, but it sounds like you have it cross threaded, o-ring jammed, or maybe even the spring sitting on the lower shoulder. It should screw right in very easily. Remove it, check the threads, and make sure the o-ring holds the spring down as far as it will sit. If your threads are screwed, or have uneven markings you probably cross threaded it. I would start with a starting tap, and after it turns smooth, go to a bottoming tap right away. You don't have the space for a lot of thread cleaning with a starter tap because it will bottom out on the seat and screw it all up. I would definitely completely remove the carb for this diagnosis and possible repair. Try again.

  • Stickshift

Posted April 15, 2006 - 09:49 PM


Just to be sure we are talking about the same critter, are you talking about the idle screw adjustment - the black knob on the left side of the carb, that has a cable that wraps around the carb to set the idle speed? Or are you talking about the fuel mixture screw on the bottom of the carb? (The one that is recommended to be replaced with a red anodized Zip-Ty fuel screw.) I'm not sure how you post images in this forum...I have owners manual images of each of these screws in place...


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  • dl19

Posted April 16, 2006 - 09:17 AM


I just guessed that he was actually talking about air screw because I don't know why he would have needed to remove the true idle screw. Good point should have asked same as you.

  • freestyle250

Posted April 16, 2006 - 07:44 PM


I am talking about the big black knob. Not the Zip-Ty. I had to remove it because I needed to remove the lower plate of the carb to access the Pilot and Main jets to change them out. But now it wont turn past a half turn, and im starting to get slightly annoyed.

  • Stickshift

Posted April 16, 2006 - 07:54 PM


I'm not sure why it is binding up on you -- I suggest removing the carb bowl screw that holds the black knob's mount, so you can straighten out the idle screw cable. Can you turn it easily now? Maybe you loosened it on the carb throttle end too much, and the thread on that end is not started properly? There is a small washer and spring on the throttle end, too; make sure they are assembled correctly. (Should be if you didn't loosen it too much during your re-jetting.) Good luck...



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