Won't start, bad has milage, gas smell

[rome_rome]

SO, my bike after storing it over the winter (with fuel stabilizer, but stupidly forgot to turn fuel off) my kat is getting horrible gas milage (close to 1/2 what it was last year) gives me a gas smell when i get off (go in my house on the computer, all i smell is gas) and now she wont start. when i try to start it, it may start for a second then turn off, and also backfires when starting (after i stop trying to start it, turn the key off, get small back fire)

So after reading a bit and asking around, looks like i will be cleaning the carbs, but while i am ripping my bike apart, do you guys recommend checking out anything else? I will also be replacing my clutch and doing a valve adjustment at the same time.

[JHONNY_ICE_420]

def clean the plugs, or just buy new ones and change the oil. With the gas on all winter, it probably made its way to the crankcase and ruined the oil (are ya 3 qts. over?)

[rome_rome]

when i looked at the plugs (you do mean spark plugs right??) they seemed fine and fired great. should i change them anyways?

as for the oil, since i got to drain it to do the work to it, it will be changed in the process