My brother and nephew used RTS 5-40 in their 'Wings, as do many 'Wingers, but both switched to the standard 15-40, complaining that the shifting felt too 'notchy' with the 5-40.
I like M1 15-50 my own self, in my shared sump Suzukis.
I like M1 15-50 my own self, in my shared sump Suzukis.