Originally Posted by
ncshp
I am one of the two people that took Chuck's advise on the XP mod engine upgrade. (completed in April 2015) I ran the 72x43 Catto prop for the first ten hours after the mod. & then as the engine loosened up it started going over redline. I put the Catto 76x42 prop on and cut 35 feet off take off and gained 200ft/minute in climb. (26in ABW) The 76x42 is a great match and very smooth prop. Turn 2400rpm on climb out @ 68mph & 2675 straight & level flight. Also running a C-85 cam that gives more torque from 2250 to 2450rpm