I had a couple hundred flights 12+ min flights on my different twist 40 models with an evolution 46 and os 61 fx. When i dropped to a 4 pitch my engines never idled as low for extended periods then accelerated back with full power w/o hesitatig or dying. Literally, it went from 10 seconds at 2800 rpms MAX w/ a 4 pitch to 5 mins at 1800 rpms w/ 8 pitch. Pitch is critical to the engine as stated in the manufacturers specifications. This wild props are fun to fly but not reliable.

if you are flying around normal you might not notice but if you glide in and then do a touch and go to a full power hover those low pitch 3d props can kill you every time.

Thats my opinion. I need to hear back. Maybe it was just the 12.25 by 375 being to small for the OS 61fx but it happened with the 46 as well. The same engines were tuned countless times. The same engines ran 10 times better with the recommended props