Hi Stan, With an adjustable motor mount, I think either the long or short shaft would work just fine on the M15. The long shaft weighs 1.1 lb more and is 5.8 inches longer according to the Honda web site. I have the long shaft with an adjustable motor mount and if I had it to do over, I would buy the same thing. Like Joe, I am happy with what I have. Mine does have the centrifugal clutch which is a worthwhile feature available in both long and short shaft models.
The best of luck in whatever you decide. Don Olson M15 Phoenix, Az _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
