I hope that I did not jinx myself in my first post about this motor as unfortunately, problems arose quite early when testing yesterday :/ I shot some video which I cut short as at about 3:50, the motor started to surge erratically, this was only the seventh flight. It is a bit hard to tell on the video as the plane was far away at the time and the Master Airscrew 6x4x3 prop runs pretty quietly.
I checked all the connections and reset the throttle points, all to no avail. I didn't troubleshoot any further as I wanted to continue testing the MA 6x4x3 prop, so I swapped a "no name" 2212/6 2200 Kv motor into the plane and kept flying. With that motor, there were no issues, so it leads me to believe it is the DYS 2600 motor and not the ESC or any other components in the plane.
I will try again in another plane with a different ESC and perhaps experiment with different ESC settings like I did with the DYS 2200 motor, fingers crossed.
One thing I did learn however is it appears that the DYS 2600 motor actually has a 3mm shaft, not a 3.17mm shaft as they list in the specs. I just looked more closely and in the diagram of the motor that displays all the dimensions, it shows the shaft being 3mm in diameter, yet in the specs list is shows 3.17. So if you are buying this motor and need spare prop collets/adapters, you will need them in 3mm, not the very common 3.17mm that are used on most park jet motors. I discovered this when I tried to use the adapter from the DYS 2600 motor on the 2212/6 2200 Kv motor I replaced it with.
Fortunately, on a brighter note, I am very impressed with the performance of the Master Airscrew 6x4x3 prop which I will continue testing on other motors I have that can swing it without issue. I will write more on that in the Props thread.