ok... i may sound stupid but my engine is runnin really rich and need to know how to lean it back out....the carb is a 600 Holly elec chock vaccum sec........im pretty for sure that the small screw on each side is what u change but what side which way to turn and how to know once ive got it leaned back out? :confused: any help would be greatly appriciated :cool: :rolleyes:

I've got a truck delivering at Weyerhauser today,down there in Valliant,Ok. I would turn both those screws all the way in,gently so as to not hurt the needle and seat,then back each out 2 turns and go from there. If adjusting those needle valves on either side does nothing,I would then pull the float bowl and replace the power valve as most likely it has blown,got a hole in it,sprung a leak. You can use a vacuum guage or tach to set mixture,adjust for max rpm at idle,make sure both mixture screws are adjusted the same i.e. both out 1.5 turns or both out 2 turns. Just make sure the timing is right and you have no vacuum leaks..

ok,by screwing them all the way in im guessing you screw em in ike a screw righty tighty..... ill give it a i kno its not my timing or the power valve cause it was rebuilt not to long ago.... there sure is alot of people on here that goes to weyco alot....

the idle mixture screws on the side won't help you if the carb is jetted too rich.

if you have a vacuum gauge, adjust your idle to 750-800 rpm for auto, 800-900 for standard, and adjust the screws evenly for the highest vacuum.

i think it is jetted to rich......

why would a car run to anybody..... ;)

when you say running rich, do you mean at idle or at WOT.

if its running rich at idle most likely you need to adjust the throttle blade/transfer slot relationship.

the only way jets will cause a carb to run rich at idle is if the carb is grossly over jetted.

im guessing idle..... can it be both? :confused:
it was rebuilt about a year ago and i wasnt the one who rebuilt it so i couldnt tell ya what size the jets are

sure, it can be rich at idle and WOT.

but there isnt much guessing here, the exhaust either stinks like raw fuel at idle or it doesnt.

as Rapid Robert said, it could be a blown power valve. it also could be the transfer slots are exposed too much. or it could be grossly overich jetting, which is unlikely unless the jetting was changed by someone who had no idea what they were doing or they didnt care. (shouldnt be a need to stray too far from the stock jetting)

either way you wont solve the problem unless you take the carb off and open it up and look at it. find out what jets are in it, check/replace the power valve/s and adjust the idle mixture screws for highest vacuum and post back with the results.

i can rule out the power valve, at idle the exhaust smells like raw gas... :( some times carbs are so damn fustrating :mad: