Hello, I have a 98 gs500.

My problem with it is that the revs are hanging and the idle is really unstable, sometimes it will stall.
Im guessing the bike is running too lean, I already cleaned the carbs 4 times with carb cleaner and made sure its all clean.
I checked and adjusted the float height 4 times aswell, using the clear tubing trick and also with a ruler.
The bike has a stock air filter and an aftermarket slip-on.
I also sprayed the whole bike with wd-40 and cant find a leak...

Help and suggestions are much appreciated.

Valve clearance?  When was it last adjusted or checked, and how many miles on the bike?

I dont know when, the bike has about 70k miles, i had it foraround 6k miles, havent checked nor adjusted the valves, and dont know when they were

Anyone?

Check the valves, then report back

hmmm  thinking leak @ intake perhaps maybe valve clearance. not sure 100%