Some questions on carb tuning...

1. You guys recommend #40 pilots. What is the stock pilot size? Will I have to replace the pilots as well as the mains?

2. What is the problem where the bike falls on it's face when you slam the throttle? I think my bike may have this...what is the cause and the cure?
Err...see that is it a problem with the carb slider. I can't find this part on my carb diagram...where is it and what's it look like?
Edit #2: are the holes on the bottom of the piston valve? Is that the slide?

Thanks 

<oops>

1. 37.5 for CA models (which you may have).
You should not have to replace the mains, but if you only want to get into the carbs once, then yes.  I did mine in stages; I did the pilots first, the washers second (one washer under each needle, and then two), and then finally I had to change to 125 mains and only one washer under each needle.  So that's four times that I had to enter the carbs (twice from below, twice from on top (which did not require me to remove the carbs)).

2. Too lean.  Mostly due to the pilot jets.  The piston valve/slider is third in line after shimming the needles.  Fourth if you include float level.