MY FOX 2.4 IS FLYING A 25LBS VAILANCOURT L-5. ITS SWINGING A MEZJLIK 20X8 PROP AT 7250RPM. IT IS EXTREMELY EASY TO START AND HAS GIVEN ME NO TROUBLE WITH ABOUT 3GALS OF FUEL THRU IT. FOX MAKES THEIR OWN CRANK AND CASE. ITS A BEAUTIFUL LOOKING ENGINE. I KNOW, BEAUTY DOES'NT MAKE THE ENGINE, BUT THIS IS ONE HORSE OF A 2.4