For the past few days, when I get to work in the morning, my idle would be lower than normal. Same thing when I get home. Last night, I smeared some grease on my idle knob to see if someone was messing with it (I would find the grease removed/disturbed). But, I had to go to the gym, and rode to a freinds house; no problem. And, no problem when I got home. But, this morning, I go out to look to see if the grease had been disturbed, and I notice that the screw had rotated all by itself (with the grease intact)!! So strange! (I did think, if it were saboteurs, they might use a right-angle screwdriver, but really, how many right-angle screwdrivers are out there.) It seems that engine vibration is causing the screw to back out. I haven't lubed the throttle cable recently, and highly doubt that any cable lubing is causing this.

Anyway, I thought I would share, and to see if anybody else had this problem.

Use some low-strength threadlocker, maybe even a diluted solution...or just a very, very minute amount.  Even though it's called "low-strength"  it might act in the capacity of high strength on such a small screw.

Sounds like it's time for some .020" Brass safety wire.  

I have safety wire, I know how, and I'm not afraid to use it.

However, the application may not require its use.

I'm going to just try to clean the threads of any 'lubricant'.

My suspicions were correct, in that it was 'lubricant' that was causing my idle screw to 'walk'. I removed the idle screw from the carbs (while they were still on the bike!) and cleaned the threads of alot of charcoal colored lubricant, I'm guessing it's the same silicon graphite cable lube that i've been using.

Good to know that we can remove the idle screw with the carbs still on the bike.