[dannylightning]

carb cleaner could work, lube or adjust the throttle cables could be the case too to check this, with the bike off roll on the throttle about half way, quickly let go, the had grip should quickly snap back and you should be able to hear it snap back if it does not snap back and you cant hear it snap back. than you probably need to lube the cables or adjust them.. if it does that the cables probably don't need any attention and i would try something to clean the carb. you should be able to wiggle the handgrip/gas pedal haha it should have a few millimeters of play in it look in the manual it should tell you the specs.

i think a lot of people have trouble getitng in to first if they are stopped. mine does this some times but if i roll the bike forward or backward just a tad it will shift right in to first. being in first before you stop is the best advice as stated by some one above me.