tonight kath and i went to our local hang out a chinese resturant. the cook gave me two pistons he had pulled out of his firewood cutting saws. huskys i think. both were scored to the point of faliure. too lean on the carburator was my guess. he laughed like only my orential friends do but understood. he said he always twisted the screw unill the motor ran fast. he is such a hard worker.