[KGBnut]

With a good needle valve, properly adjusted float, and a good shut off valve you can still get a carb drip out of the air inlet. In my experience, it is almost always bad gaskets (fiber washer) on the Main Jet, or the Cap Jet. If that is the case, even with a good shut off valve, it will drip until the float bowl is empty.

Inspect and clean up the mating surfaces and replace those gaskets. Get them good and snug, but be careful not to over-tighten them.

In rare cases the Main Jet or Cap Jet can be too short. I'm not sure how this happens, but I have seen it. If either is below the float level, even with a good shut off valve, it will drip until the level in the float bowl is below the top of those jets. The only way to correct this is to replace them with the proper length...just buy new ones from a reliable supplier. (As a temporary fix you can lower the float level below the top of those jets.)

I hope this is helpful.

Ken