Joe Minton kit works, ran it for several years, I also tune with a AFR wide band reader, it works too. The Mikuni tuning manual is a good one, owners can become familiar with tuning with it.

It is really hard to read by a plug now a days with color except pig rich readings, plug does look lean but conflicting because a Mikuni is known to be rich out of the box to cover a wide variety of engines but fuel mileage is weak and the reason Joe M who wrote the tuning manual for Mikuni created the mileage kit. Anytime it pops out the intake is a lean condition, lean can also pop out the exhaust on de-accelleration, rich can lag when rolling on the throttle.

Attaching a paragraph from a Evo member
The idle mixture screw is actually called the pilot air screw, it's purpose is to adjust the idle mixture. It only affects idleto about 1/8 throttle. If you are under one turn out you are too lean and should go one size larger. Conversly if you are more than two and a half turns out you are too rich and should go down one size.

 

 

What exhaust are you running?

 

 

Put baffles in it.

 

 

Sucks to tune which you are finding out.

 

 

Is that at an idle?
Or a full load shut dwn?

 

Idle for a few seconds after a ride. Didn’t have a chance to do a full load shutdown. When I have my days off in a couple days I’ll get to that. Just trying to get the most out of what I have. Not really worried about big numbers, just want efficient.