on the carburettor there should be 2 screws, labelled hi and lo, they are needle valves. the lo one controls the idle speed, hi controls throttle speed. unscrew the lo one to increase the amount of fuel entering the engine at idle. if no labels, lo is the one nearest the air intake and choke. also, there may be another screw which sets the position of the throttle at idle, by physically controlling it. try increasing this if it exists.
steve, May 2005
