The 14-6 is way too small for this engine, it is designed to run large props. The carb is the same one as the 55, a 9mm throat so it won't do 16K very well. The engine could easily handle larger props than the 15-8 i used. It is hard to compare to a 'normal' 91. It definitely has way more power than a supertigre 90 I also run.