Bike Stalling

[brainbug007]

Hoping someone can offer some advice on this one. My bike has started stalling on me alot. Especially when I come to a stop? After a stall it's a right git to get started again and makes alot of poping noises which sound like they're coming from the carb/airbox. I've tried giving it a bit more fuel with the mixture screw which didn't make any difference (difficult to adjust as the carb has to be removed, currently set at 2.25 turns out which is the max they haynes manual recommends). I've also tried putting the idle higher but that doesn't seem to want to go any higher. The haynes manual recommends 1500rpm and mine sits at 2000rpm and sounds like it's gonna die any second. I've tried putting it up towards 2500 & 3000 but then when you blip the trottle the engine just keeps going and takes 5-10 secs to then fall back down to idle?