I adjust the valves every 7000 miles. exhaust valves are usually too tight and need to be loosened. maybe a intake valve needs a slight adjustment. after the clearances are set the engine runs noisier. On my 1990 when i first did a valve job i noticed an improvement in starting and better performance, it was long overdue for probably its first valve adjustment.(bought it used) the next 2 OR 3 valve adjustments were done as scheduled just to keep the engine running in top condition.
as for carb synching just synched the 90 after the valve adjustment. it wasnt off much but it made the engine run smoother. my new 07 checked it after i adjusted the pilots and valve adjustment. it was barely off. felt a little smoother. for carb sych tool I used something similar:http://www.motionpro.com/motorcycle/partno/08-0411/