On the man. the YS-63 has more power than an OS-70 or Saito-65 but the Saito 72 has tons of power and is lighter than the 65-

etc, etc.

The Magnum 52 4 stroke does not have more power than the 2 stroke 46 period>.

The Magnum 91 is light and they are surprisingly good engines! As are ASP- (same thing..)

Good luck,
james