Thoughts I’d throw this out for information.
Most of the screw heads on the Jap carbs you’re running (Mikuni or Keihin) will require a JIS screwdriver. A lot of the screw heads get mangled due to using the wrong (phillips) tool.
The JIS screws are identified by a punched “dot” on the screw head.

 

Good tip and absolutely correct!

 

Grinding the point off a US phillips will help
Installing hex head screws helps more

 

Here's a pic of them all.

 

And they are expensive, off brand tools. I've changed some to stainless Phillips but would like to find a set of reasonable price drivers.

 

reason the first time in, they go stainless allen head (some use socket head)

 

I use SS allen heads, can get them at a good hardware store. They are metric, can't remember size but there are previous postings on this very topic for the exact size and length.

 

The old JIS rears it’s head on the petcock as well…

 

M4 x.7 x 12 covers the bowl & accel pump
3mm hex key

 

easy peasy