Screwing air adj in on carb.

[subanator]

My bike wants the air screw adjusted right in almost (Mikuni carb), so is this running lean on the pilot jet and needs a bigger one?
Idles ok, but needs to get away without bogging by this adjustment.

[Lozza]

Air screw on just about all carbs is 3/4 to 1.5 turns out. Less turns bigger jet more turns smaller jet

[All Things 414]

It sounds like you need a smaller larger pilot. 
BE AWARE
I know subanator is talking about a Mikuni here and as stated most carbies are the same however I got into all sorts of strife a couple of years ago when I bought a brand new Bing.
I thought it was strange that the air screw was to the front of the carb (in front of the slide) and when I tried to tune it using this screw, everything was up the put. It wasn't untill a passing rider (upon hearing my abuse) told me that on some Bings the screw actually adjust the fuel going into pilot circuit, not the amount of air.

Now all is well. 

[Viper79]

Here's a extract from a Mikuni tuning site.

The pilot circuit has two adjustable parts, fig 2. The pilot air screw and pilot jet. The air screw can be located either near the back side of the carburetor or near the front of the carburetor. If the screw is located near the back, it regulates how much air enters the circuit. If the screw is turned in, it reduces the amount of air and richens the mixture. If it is turned out, it opens the passage more and allows more air into the circuit which results in a lean mixture. If the screw is located near the front, it regulated fuel. The mixture will be leaner if it is screwed in and richer if screwed out. If the air screw has to be turned more than 2 turns out for best idling, the next smaller size pilot jet will be needed.

[subanator]

Cheers for info. Yes I am aware the Euro carbs like Dellorto and seems as described the Bing do adjust differently to Mikuni's.
My screw is locate to the back, and if adjusted out too much it will get a flat spot off opening throttle. Turn the screw nearly in is able to sort this, but I dont think I have any adjust-ability like this.
Going by what Viper79 posted, I will need to go up a size on the pilot. Sizes are in #5 increments I have seen. I suppose this is a starting point and see what happens.

[Viper79]

You're right, if you are screwing the mixture screw all the way in to get it to run better, it is too lean on the pilot circuit.
The screw regulates the air to the pilot jet, in your case I would imagine you need to reduce the air to richen it up, so you will need to go up a size on the pilot jet

[pmc57]

Viper79, are you sure of your description of the pilot jet? How I understand it the air screw regulates the amount of air going to the pilot jet. The pilot jet regulates the amount of fuel, the air screw adjusts the air that mixes with the fuel from the pilot jet. Therefore if he is runing lean in this circut and needs to have the air screw nearly all the way in, he will need to go up with the pilot jet. Most air screw settings are around 1-1.5 turns out, so if he's lean at 1 turn out he needs to have more fuel on the pilot circut to richen it up. He should also check he's got the correct cut-away in his slide as well, if it's too big that can make it run lean around the low throttle range as well.

[oldyzman]

I think you are right PMC, re the screw and jet kinda being opposite... As long as the screw we are talking about is at the back of the carby
Brett

[matcho mick]

79 just confused himself with L side brain overriding R side which controls typing finger

[subanator]

Ok, I think I have it now!
Yeah, I went up 2mm bigger with a carby size, from a VM22 to a VM24, airslide 2.0, ok for the low end response I need.(trials)
Added Boyesens the other week, did settle it down a bit, but another future mod increasing the reed block will change this again.
Saw the other post on the reed spacer, tried that and totally killed mid range response (as I am trying to increase it), but better low end response.
Too much impatience and did not try each mod on their own, as dont know what is effecting what, will pull the spacer out and try again soon and with another pilot jet.