After looking at your thread I am starting to wonder if I need such a small main jet for my 19mm PHBG because my pilot is also very big.

Do you know if the pilots contribute to the fuel delivery at all rev ranges?

I think my PHBG has the wrong 4-stroke style atomiser and/or maybe the pin is tapered too steeply... did your Mikuni come from 2 or 4 stroke motorcycle?