I am going through jeting my bike & Mikuni for CO.

Your pilot jet sounds way small, from all the data I have from everyone that posts here it usually runs about 26-31% of the main jet.

One thing i noticed on starting with the stock carb, do not ... do not twist the throttle when starting, don't even touch it, only use choke or nothing. Opening the throttle ruins the choke system (which really is not a choke system as typically on a car).

I don't know on a Mikuni if it has a real choke or suffers the same problems as the original carb. I use the no touch rule always now too.

 

The Mikuni you have has a fuel based enrichening circuit somewhat similar to our Keihin CV. You're right on leaving the throttle completely closed when using the choke for optimum effectiveness. Opening the throttle reduces the ability of the engine to draw fuel through the choke fuel circuit.