About those airscrews.....I had a rough time with mine until I figured out the best way for ME to do it. I tried using the instructions in the service manual, but I just didnt have much luck there. I would adjust the screws and wait and just not get much difference. I attribute that to not using a digital tach since I didn't have one. I don't think the one on the bike is accurate enough to see 50 rpm changes.
With that, here's what worked for me. I set the screws out one turn, on my bike that is way rich. Then I grabbed a long skinny screwdriver and hit the road. I found an empty road that I could cruise at 35-40 mph without being bothered, and pull over frequently. I cruise at 35-40, in 5th, very light steady state throttle, and noted the behavior of the motor. An overly rich airscrew will burble and miss and be very annoying to ride at that throttle setting. It will have okay throttle response though, it wont die when you open it up briskly. Stop, adjust them all out 1/4 turn. Ride, and note. After a few stops and adjusts the burbling will go away, little by little. When it starts to cruise smoothly, make sure you briskly open the throttle and see what it does. When you start getting too lean, it will start hesitating or bogging on brisk throttle opening. You will likely never be able to whack it wide open without killing it (no accelerator pump) but you should be able to open it briskly.
A couple of caveats that I learned. It will be harder to start cold the leaner you go on the airscrew, you will need more choke for longer. When my bike was way to rich, I hardly needed any choke at all. Throttle response will suffer if you go too lean, as will idle quality. The setting I ended up settling on was a compromise between cold starting ease, idle quality, and burbling at very light throttle settings. I have a good idle and it starts well enough cold, but still has an ever so slight burble.
Dont know if you need this info, but it seems like you might be messing with those airscrews soon.....