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Discussion Starter #1
My idle screw keeps going out of adjustment and I finally figured it out. I can go for a 30 min drive without any trouble, but as soon as I got on it hard after driving at a steady speed the car would no longer idle high enough.:( Well tonight, it happened again and I marked the idle screw last time I adjusted it, because I had a feeling there was a problem, and sure enough it's backing out. The problem is the bottom of the idle adjuster screw has a high spot, so when I turn it 180º I can see the throttle go up, down and back up again. Will this screw back all the way out so I can grind it flat or will I need to do it while on the carb?
 

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Discussion Starter #3
Maybe a bit of red loctite on the screw will eliminate this problem.
Oh never even thought of that idea, thanks!:yes:
 

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Is the small cork gasket in place in the screws hole? These usually keep the screw from moving around.
 

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First pic is parts:
Reference new needle valve, & cork seal & old needle with seal



jet plate has a recessed area for cork seal


Cork seal installed in jet plate


Needle installed


Late model carbs have a more recessed area for the seal, some also have locking plastic caps



I have done O-Ring option Just put some WD-40 during install
 

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Discussion Starter #6
Is the small cork gasket in place in the screws hole? These usually keep the screw from moving around.
I didn't see one, I backed the screw right out and filed it flat. There was a low spot on the screw really close to the where I had it set for my idle around 7-800rpm. Any movement would and the idle would drop to 500rpm.

Taz I will have some pics for u in a little time.

Al
Thanks Al.
 

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Are you talking about the idle speed screw on the throttle body? All these pictures of mixture screws have me confused.
 

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Are you talking about the idle speed screw on the throttle body? All these pictures of mixture screws have me confused.
Opps good call!!!!!!!



needs the spring!!!!! If spring is weak stretch it~
 

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Discussion Starter #9
Sorry guys, the idle mixture screws are OK, it the actual idle speed screw causing the problem. I think I have it sorted out, when the rain stops I'll take it for a run to make sure. I was wondering what you meant by the cork, the posted info is good to know as well though.
 

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Whoops, misunderstood that one. Yea, make sure the screw bottom is flat, and make sure the spring has good tension on it. I don't know If I'd use red loc tite on it though, maybe something less agressive like the blue.
 

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Discussion Starter #11
Whoops, misunderstood that one. Yea, make sure the screw bottom is flat, and make sure the spring has good tension on it. I don't know If I'd use red loc tite on it though, maybe something less agressive like the blue.
Yeah I'll put a dab of blue on it. Spring is good and the carb is brand new. I thought it was something going out of tune, but every time I readjusted things I ended up with everything right back where it was except the idle speed screw, so I marked it the last time I reset it and figured out last night the screw had a low spot. I'm glad it was a simple fix.
 

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idle screw..

That screw is referred to as the "curb idle" adjustment....sometimes a sloppy throttle shaft or weak return spring will also add to the problem. The curb idle screw threads should fit nice and snug on the carb...you can always steal an adjustment screw form another carb and try that.

wilma
 
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