I believe the stock 110 carb was a 20mm Keihin.
I have several 110 carbs right now, but have yet to go over them carefully, except a few "extras" that I threw on eBay because they were all misc left over pieces. The 155 stroker
motor ((
Internal Combustion Engine ? )) we have has a larger carb, but I haven't looked at it close enough to tell you what size it is and we will probably be keeping that one anyway.
If you have a 28 on it, it's probably better off except for the clone issue. You gotta wonder how much "tweaking" the clone engines can take anyways since the parts have much lower tolerances and lower quality materials to begin with, I know, we have a CRF50-110 clone that runs fine, but the workmanship is terrible up close, too many poor fitting stamped sheet metal parts for my liking.
Just my opinion.