Small 25cc four stroks have no more torque than the same size 2 strokes...a 25 cc Honda or Shindaiwa turns the 18-6 Mejzlik the same rpm as a G23, same with an 18-8..A 20 inch prop really drags one down..Been there....
have not seen a Ryobi or Stihl, can't see how it could be much different....