Can you adjust all 4 pilot screws without removing the carbs fron the bike? Looks like a tight fit to get the two inside ones.

 

straight blade screwdriver with a shaft that is about 8 - 10 inches long works good. There are some specialty tools that might work better (I don't know) but I have never had any problems.

I do make a mark on the handle of the screw driver to make it easier for me to count how many times I have spun it around (I usually do a quarter turn at a time so the index mark makes it easier).

KongBastard

 

Not sure what the F1 carbs look like, but on the F2, you can access them off the bike with a pilot screw driver. Otherwise on my bike it it would take child sized hands to do it.