thats it!
spray all inside and wipe clean, mine was black and loads of crap come out, chuck some fuel cleaner in the tank aswell
you can also get the engine hot, remove pipe to airbox whilst still running, rev engine high then spray some carb cleaner up the pipe into the air intake, small bits at a time, it will cough abit but it will clear, if you see whte smoke coming out the back yo have carb crap build up, keep spraying and it will stop white smoke