t's really very easy to add a vacuum port to the carb.  Lancer explained it as follows:

Quote:It is very easy to do.  I picked up a little baggie of brass tubes at Lowes, about 10/bag, 1/8x1", with a slight bell flare at one end.  I cut and filed the flare off so it is straight on both ends.  On the engine side of the carb bore, at about the 2 oclock position (almost but not quite under the choke handle) I drilled a tiny hole (about 1mm) through the  carb wall, then drill another hole on top of the little one about 3/4 on the way through the wall (leaving a floor in the hole bottom)...the same diameter as the brass tube...then using epoxy glue set the tube in the hole and tap lightly to seat it securely in the bottom of the hole.  I angled the drilled holes a little toward the engine.  
 
The entire process takes about 5 minutes to do, then you let it sit until the epoxy is completely cured.  Some epoxy's will set in 5 minutes and others take several hours...just a personal choice depending on how you like to work.  



I picked up a small brass hose splice from Home Depot, modified it slightly by  shortening one end of it to fit into the dual-diameter hole arrangement Lancer described and used metal epoxy (which is the same color as the aluminum carb) to fasten it.  It has a wider band in the center of it that creates a nice base against the carb and more surface area for the epoxy.  It actually looks like it was made as part of the carb except that it's brass.  The ridges on it are designed for a solid airtight splice without using hose-clamps, so it may not allow the tubing to be removed from that end without cutting the tubing but that's okay by me.  The only thing I overlooked was angling the hole(s) toward the engine.  It doesn't seem to have adversely affected its operation though.
I was looking at doing this and was wondering if maybe one of you had a picture or two of your carb and placement the tube you installed or any other helpful tips. thanks 8)

thanks very helpfull