Now I get it. The main on the cdh one's I'm getting are 20.3mm abv. metal. I guess +- 1 mm probably ain't gona be noticed much anyway. Lately these carbs have been a real consistent 21mm at the float. Kinda nice for a change.I have a stick on a key ring that I used to use to measure at exactly 21mm - maybe just because there are so many hills here or that I prefer a bit rich over a bit lean for safety with noob riders, but for many years I've measured by the main since it is easy to understand by noobs and works well - next time I have one apart, I'll see what the measurement is at the main. That 21mm figure is from a diagram from about 10 years ago of the first delorto clones and may not be right (but close enough) for the NT clones.