I have flown this set up for a little while

aeroworks 50cc ultimate
18lb with everything

Rimfire 65cc
cc160hv
3 blade biela 24x12
2 6s 5000mah

Ok now for the problem I bought a mejzlik 24x12 3 blade prop thinking I would get more out of a thinner blade !! Well I run the plane up and at 60% throttle it shuts off will not spool at 100 % I look at the data and it shows 9000 and 9500 rpm so I am guessing it is over spinning !! can I resolve this or should I look for a different prop any ideas or suggestions would help ! ps the 3 blade is for ground clearance had a 26x 13 2 blade to test had ground strike !

You may want have another look at your data. 12s is about 44v under load, that x motor kv = 7040rpm. In fact my 6s x2 show 42v. If your using a tach, is it set for a 3 blade prop?
Two things to watch for here, the extra weight of the cf 3 blade could be loading the esc beyond it capacity. The other is the throttle endpoints, I don't rely on the auto set features, I use the set endpoints to ensure 100% travel thru the Tx throttle range.
Use a know n wattmeter to verify whats happening. A 24/12/3 blade may be beyond esc and motors capability. fwiw Doug B

I just completed a 50cc pitts using a suppo 5345/8 motor,castle 160hv castle 20a pro bec and a biella 20x10 3 bladed prop with awsome results on 12s. I guess it could be prop issues but im not a pro on these matters.

Brushless 50cc pitts (1 min 9 sec)

This is my setup

the data I got was from the esc datalog I have run and flown it with a 24x12 3 blade these pics are from the neat fair this year I flew 10 or so flights . The problem came when I switched props same size just went from biela to mejzlic same size ! just trying to figure out the problem !! I put the biela prop back on and spun it up todat it ran fine and pulled well didnt fly but static test !!