I took my carbs out to clean them and the bike has not been running good. I set the mixture screws to 2.5 out and set the idle after warmed up. once i rev the engine it hangs and wont come down. I lubed the cables and it snaps back fine. I noticed that the airbox and the little round rubber/spring seals that are seated close to the carb intake side, are not fully sealed to the intake side of the carbs. I tried to slide the airbox closer, but it just wont go any further closer to the carbs. Any ideas?

I was thinking of drilling new holes below the battery so that I can push the airbox further forward, then tighten the screws below the battery. I believe this is my issue of hanging idle.

Jonathan
aka fixture

Jonathan - take a look at Kelly's post on this issue.

You need to fix that. You are sucking in unfltered air through that opening as well as leaning out your mixture by letting too much air in. A hanging throttle as you describe is a classic sign of a too lean idle mixture circuit.

Don't just richen out the mixture to fix the problem. Fix the intake gap between the carb and airbox first, then work from there.

http://faq.ninja250.org/wiki/How_do_I_adjust_the_idle_mixture%3F

Also if you search the pre-gen tech area for "airbox" you will get some other hits that might help in re-seating the airbox.

spend 60 bucks
and see pod thread
and 10 bucks for main jets and a couple flat washers
and see jetting thread