I've never had a prop kick loose from being too rich.
Only happens to me when the needle is set too lean.
Check that your fuel tank is at the proper height for where the carb is located.
Make sure that the fuel passages in the carb are not obstructed.
Also make sure the clunk in your tank is not stuck up at the front of the tank..
I've also never run fuel as low as 10%.
Lowest I've ever used is 20% nitro.
I've run Saitos, OS, YS, and Thunder Tiger 4 strokes and not had this type of problem unless the fuel flow was restricted in some way.