ORIGINAL: airraptor
this is a common problem on all the AX engines above 55. my 120 now will now stay running long in the midrange now matter what i do to the idle setting. a 17x4 seems alittle on the small side. i ran a xoar 17x6 with stock muffler and pulled just fine at 10.5 lbs. it wasnt electrice 3d power but would pull out slowly. with a pipe it spins the APC 16x8 at 9,800 peak and about 9,600 just right
The 17 X 4 does seem small by "spec"...but I have tested many props with RPM guage and digital thrust guage, and I found a 17 x 4 (w) spools up fast and gives tonnes of bottom end. On a 10.5lb plane, I set my 17 x 4 to 9600 RPM (nice and rich)....and it pulls out of a hover faster than any electric ! Within 5 seconds it is out of sight. If you do 3D, try an APC 17 X 4 (W)...you'll be amazed at the vertical pulling power.
In level flight you stay below 1/2 power (will over rev), but in vertical climb, it pulls amazing. For $20 its worth a try
