stock 03 xr 50

bone stock

needle was at 2nd from top, and the bike didn't want to idle, and it has a low end bog, if you're at idle and you mash the gas it bogs, then you let off a slight bit and it picks back up.

i have messed with the air/fuel screw but to no avail.

any pointers

set for good top and good low

 

THATS THE RIGHT SPOT FOR THE NEEDLE STOCK, BUT I GUESS IF ITS GETTING TO MUCH GAS OFF IDLE RAIS IT UP ONE ... YOU SHOULD ONLY HAVE TO MOVE THE MIXTURE SCREW IN ???