stealth adjustment screw question

3 replies to this topic
  • runester

Posted May 10, 2007 - 04:41 PM


Hey all...O.K. after pulling the carb a dozen or more times and switching everything out (see my earlier post) I finally found it was the stealth fuelpump cover that was causing the DEATH of my new baby...however, I have a question about the adjustment screw I got in BUT it runs best at 1/4 turn out!!!! Is this right!!??!!??I am new to these screws and they are #d 1-4 is it normal for a quarter turn on these to equal 2 turns on the stock screw? Here are some photos...does the stealth screw seem narrow??it is a bit hard to see in the picture but up close it looks WAY tapered compared to stock. Is this O.K.,normal? There is NO MENTION of it in the instructions.

Everyone I want you to know I come seeking info w/humility I know NOTHING about these four strokes but really want to know as much as I can digest. Of course carb work can be a hassle and these carbs have alot of parts and a completely different architecture than I am accustom to.
As I write I am back to the stock fuel pump cover... replaced the 45 pilot w/a48
and the 60 main w/a68 and the stealth fuel screw is at 1/4 turn out but stock was at 2 turns out for the same behavior.
Please chime in if there is ANYTHING I should know...
Here are some photos of the screws etc.PICT1945.jpg



  • runester

Posted May 10, 2007 - 04:42 PM


Whoops grabbed one of the old lady by accident...
Just ignore that one...

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  • CaptainKnobby

Posted May 10, 2007 - 05:33 PM


Depending on the tempature outside and the elevation you ride in depends on the # of turns you go in or out on the fuel screw. On these four strokes you just about have to adjust the fuel screw as the tempature rises or declines. I found on my yz450f at temps from 30 to 60 degrees it runs best with the screw turned out 3 turns and 2 1/2 turns out when the temp is from 60-70 and this past weekend when it got 82 degrees here I went 2 turns out and it ran perfect. Hope this helps you.

  • HappyG

Posted May 10, 2007 - 08:44 PM


i guess the tolerances on the stealth screws are not that great. mine was noticably fatter, so required almost a full turn more than my stock one. my freinds one was thinner than the one i had, but still bigger than his stock one.

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