Originally Posted by Oregonite
I have a Holley 390 cfm 4160 carb. on my Jeep AMC 258 c.i. and noticed that one of my air mixture screws is really sloppy and loose fitting. Would this affect the air mixture and the way it runs? Would replacing the air mixture screw gasket fix it?
If you don't have access to the cork o-ring/gasket seal dealie, a rubber o-ring can be substituted. Pep Boys used to have a tray full of small O-rings, so did Home Depot and Lowe's (small bags of various sizes, that is). Otherwise check at a NAPA. Most other auto parts stores carry those dreadful "HELP" aisle carded parts and they'll have some o-rings but the cost will be way more than they're worth.
If you are in a real bind and cannot get a cork or rubber o-ring, if you are careful you can give them a couple tight turns of teflon tape. You need to keep the tape off of 1/2 the threads towards the needle; only tape on the half towards the screwdriver slot.
If you do this, you need to know that the tape will come off in the threads of the carb and if the screw is fully removed after the tape is applied and the screw fully installed, you will need to clean ALL of the teflon strings out of the throttle plate and mixture screw threads before putting the screw back in.