Won't return to idle

[troyaj2]

95 Kat 600. After messing with the idle adjust screw it will idle steady. If I rev it up it will stay there for some time and will sometimes continue to climb on its own. I have tried spraying carb cleaner on everything to search for an intake leak and the bike will not rev when I do this. What should my next step be?

Thanks!

[skjeflo]

Is the plug in place on the end of the air box drain line? Is there even a drain line hooked up?

Is the valve cover to air box line in place and sealing well?

Vacuum hose for petcock in place and in good condition?

Factory or Emgo paper air filter? K&N filters cause problems.