Holley 4 Barrel Carb screw ID

[further]

Can someone assist in identifying the screw noted with the ? on the attached photo?
Thanks in advance

 

[Scott Danforth]

Holley carb 101

Idle mix screw. Should be one on both sides of the metering plate

 

[further]

Ok thanks Scott. So, had the carb rebuilt last month and everything was set perfectly and ran perfectly. Took the boat out last night and on startup, noticed the tach reading way too high on idle, so in my frantic madness (don't ask why), i turned the idle mix screw instead of the idle speed adjustment.... Turns out the idle was perfectly fine - tach was stuck!! tapped on it and it came back down, so i adjusted the idle speed to where it should be (around 600 in gear) but noticed the motor vibrating a bit more and kind of surging when I went to restart towards the end of the night...
Did i mess it up? I freakin hate adjusting/tuning carbs...ugh.. truly a black art.

 

[Jason89sunbird]

Lol, what I would do is find the screw on the other side of the carb, like scott said there would be. Turn that screw in(clockwise) while counting the turns until it lightly bottoms out. Then turn it back out(counterclockwise) the same number of turns. Go back to the screw you messed with and lightly turn it clockwise to seat it and then turn it out the same number of turns as the screw had on the other side. The 2 should match, they each feed the idle fuel for half of the engine.

 

[Scott Danforth]

its not a black art, its merely understanding the carb and its simplicity. As Jason indicated. count the turns on the starboard side of the carb, then match them

 

[further]

Thanks guys. Makes sense, will try. Scott, starboard side? Not on the same side but aft behind the throttle?

 

[Scott Danforth]

when facing forward in the boat the Right hand side is the starboard side, and the left hand side is the port side.

 

[further]

when facing forward in the boat the Right hand side is the starboard side, and the left hand side is the port side.

Scott, I know what starboard and port are. If you look at the photo in my original post, there is an idle mix screw fore of the throttle and another similar looking screw aft of it. Is it that one or should there be another similar one on the starboard side of the carb... that's all I was asking.

 

[Scott Danforth]

the trottle shaft stop (idle speed adjust) are only on the port side. the metering plate has an idle mix screw on both port and starboard side.

 

[Jason89sunbird]

Further the communication problem is that you are using the word "aft" lol. The mixture screws are on the right and left side of the carb not forward and back(aft)

 

[kenny nunez]

Is the picture of the carberator the one that you are asking about. If it is then it looks like it has 4 corner metering idle mixture screws. Most of the time 1.5 turns from lightly seated puts it very close. If it does have 4 metering screws you may have to try 3/4 from seat.

 

[further]

Thanks all... I got confused - the pic i attached is not exactly the carb i have and shows 4 screws as kenny nunez mentions. My carb has only 2, one on each side port and starboard so all good. Went out to the boat this weekend and followed advice.... the side i didn't touch was 2-3/4 turns out from lightly seated so I adjusted the side i unintentionally messed with to match. Didn't get a chance to put the boat in the water yet so hoping all will be fine when I do this week sometime.