How to adjust idle speed on 1915cc

Dual carbs or a single? If duals some specialized equipment is needed (unless you have VERY trained hearing). The prices vary for syncronizers but are reasonable (appx. $30 and a GOOD investment). You'd do well to get one and learn it's use.

Dual Carbs, I have AC and the engine stalls when I come to a stop. Assuming and based on a previous post that the idle speed needs to increase to keep the ac running at a complete stop.

I've read that the best thing to do before adjusting your carburetors is to first adjust the valves then check your dwell angle (if you have points) and ignition timing:   Valves, Ignition, Carburetion (VIC).  I think the reason for doing this is that many people first try to adjust the carburetors to compensate for an engine that has ignition or valve issues.  They end up missing the underlying problems and run an engine that is out of optimum tune.  Valves and timing are not difficult to adjust and you're supposed to check the valves and dwell on a regular basis anyway.       

I've attached a guide I think I pulled from the samba that goes into great detail about the adjustment of twin carburetors on VW type 3s.  Your carburetors and linkage are probably not the same as those discussed in the guide but they are probably close enough that the steps recommended are just as applicable.  I found it really useful in adjusting my Kadrons.     

One other thing - the guide recommends using a unisyn to balance the carburetors.  You can still get these but I think the preferred tool today is what is nicknamed a "snail."  They don't choke off the airflow like the unisyn and are easy to use. 

BTW - what does your tachometer read when you're idling?  The consensus seems to be that it's best if it's between 750 and 1000 rpms.  If it's a lot more than 1000 then the problem might be caused by something else. 

The pictures in the guide show you where the idle screws usually are on dual single-barrelled carbs.  They're very close to the linkage arms.   

I also forgot to actually answer your question.  Is it something you should do?  Adjusting the carburetors is something a person with no engine tinkering experience can do provided they are mechanically inclined and have the time to learn about it and time to do it.  Apart from pulling spark plugs, I had no engine tinkering experience before getting my VS and I think I've done an o.k. job with the carbs.  The time consuming part is the adjustment of the mixture screws which you're supposed to check every time you adjust the idle screws (a key tip that's in the guide is that these are supposed to be adjusted a little rich).  It can be frustrating but the satisfaction when you're being pushed along by a smooth and happy engine that you've tuned yourself is pretty sweet. 

As for the valve and ignition stuff, a good book to have is probably the first idiot's guide - John Muir's "How to Keep Your Volkswagen Alive."  I would recommend it as well even if you don't want to work on the car but still want to understand what your mechanic is doing to it.