Fuel andThrottle cable (?)

I have been reading that it is possible if your bike does not use the center stands then you can get some gas out of the over flow tubes - (I am using the side stand, I dont have center stands anymore) Is this correct? At first I thought it was the leaking petcock problem but now I am not sure.

Also I had a problem with my carbs leaking gas - I thought it was bad gaskets - Because gas seemed to be coming out of one of the carb bowls (where the bowl meets the rest of the carb) - SO I ordered some new gaskets and the samething is happening - Any ideas -

Last question - When I give the bike gas the throttle does not snap back - I noticed a "piston" on the outside of the carbs could this piston be bad - Not causing the throttle to close when I let go? - The throttle never really closed all the way before I took the carbs out - But now it is not at all

My bike doesn't have a center stand, and gas will sometime leak from the LH carb when on the side stand, IF if forget to turn the petcock to OFF. The owners manual for my bike says to always turn the petcock to OFF when parked, so KAW may have been wise to the chance for a leak thru the carbs.
If your petcock uses vacuum, then I don't know about it. Mine just says "On, Off, and Res".
Your throttle may be sticky because the cables need lubricating. Before I lubed my cables, I could almost use it as a cruise control. After lubing, the throttle grip snaps back nicely.