Did you clean and inspect both the slow/pilot jet and the main jet? (These are the little brass thingys with the holes in them that screw into the carb).
The slow/pilot jet influence low end fuel delivery. To adjust the amount of fuel delivered, you switch out jets (A bigger number means more fuel)
The taper and diameter of the needle (the big long needle in the middle of your carb, connected ot the throttle) controls how much fuel your engine gets at midrange. The clip has ~5 notches that it can snap into. The higher the needle sits (moving the clip to the pointy end), the more fuel your engine gets at midrange.
The main jet controls the high rev fuel delivery. Like the slow jet you need to change them out, no adjustment. To adjust the amount of fuel delivered, you switch out jets (A bigger number means more fuel).
If your bike is running hot, that's a sign that it's lean, and needs more fuel.
If your the carb has no clogged jets, AND your bike has no air leaks, then the easy option to richen up the midrange is to move the needle clip.
FYI, If your intake boot is cracked, then the engine can suck in extra air and lean itself out. Check the intake boot for cracks.
Odds are that the needle clip position is not the root cause. But it WILL influence the way your bike runs in the midrange and can be a good diagnosis tool, and temporary fix.
Look at the jets really really close.
EDIT: To set the float level. Pull the bowl off the carb. Tild the carb back/forth so that gravity is opening and closeing seat. Observe the angle of the float arm as the seat closes, it should be PARALLEL to the edge of the bowl. If not, bend the small tab to make it close when the float arm is parallel. This is a general rule, and works pretty well.
Linkys:
http://oldmanhonda.com/MC/Rcarbs.html
http://www.dansmc.com/carbs.htm
