I recently bought my son a used 98 kx60 and when he slows to turn the bike bogs and sometimes stalls. I have removed the carb and cleaned all the jets, etc, cleaned and reoiled the air filter, but with the same result. The bike starts in one or two kicks, idles fine and runs well when riding in a straight line. The bike was ridden pretty hard by the previous owner. Any help is appreciated. Could I have a problem with crank bearings?