I have a Collari .30 that the slide in the carb seems to hang up a little. It uses a 2 needle aluminum Sirio carb. At a certain point in the idle speed screw adjustment the slide will stick. The motor seems to hold a tune just fine but I can't adjust the idle just right.

Could I use a different carb, say...from a .21?
Would manufacturer make a difference? O.S. RB, etc.