[bingo2]

I'd like to add to my previous post.

It appears you've made at least one change to the carburetor to allieviate an off idle stumble; you changed the nozzle size.

Hopefully, before doing so, you went through the basic setup for your carburetor.

An off idle stumble can manifest itself in many ways; for instance, improper initial timing, incorrect setting of the idle mixture screws or improperly sized idle feed restrictions, a vacuum leak, float height, just to name a few. Changing the nozzle size may have masked the real cause of the stumble.