Hi Norm,
I hear what you are saying but cylinder cut mowers are better with slower engines while 2 strokes are generally used in high revolution situations where power is what its all about while cylinder mowers require more slow and constant thus the 4 stroke is used in this environment.
BTW the 2 stroke was used on earlier SB's and Victa imperials but without much success, thus the move to 4 strokes until the end of their production.
Cheers,
BB.