As far as knowing measurements of power i put power output on controller from 100% to 97% then I get full range of throttle I do this under p-settings when above 97% throttle cuts no idea why
Ah, well, that doesnt' actually tell you how much power you are getting or at what power it cuts out. You have to use some form of measuring device or test equipment that measures either watts or volts and amps at the same time (v x a = w).
When it was at 100% did it perform differently?
Just curious: why change it down from 100% if you wanted *more* power? (doesn't make any sense to me, since you can't normally get more power by decreasing the power level setting)
Same results under load or not
Then the battery test (as noted at the end of the post) is probably not necessary, as it mostly applies to loaded systems taking too much current and the battery dropping in voltage so much the system cuts out.
System has done this from day one and got replacement
and same results
Then it's not likely to be a fault, but rather a design limitation of the system, or something actually designed into it on purpose to protect parts or for legal reasons.
Many systems have power or speed limits or both, though they don't normally cut out at the limit, they usually just roll back the controller output to the motor to maintain that limit.
If yours has a speed limit, it will stop increasing speed above that limit whether the wheel is on ground or off.
If it has a power limit, that can only be tested on ground while riding, but there are is still a test for it, if you have a way to measure the actual power (watts) or current (amps) the battery is supplying to the controller. You measure the watts or amps during cutout while riding on flat ground, and then do it again while riding up a hill. If the number is identical in both cases, it's power or current limited in a strange way.
For battery voltage not 100% sure for test you are saying
but I do have full charge
What is "full charge" for your battery (actual voltage)? (normally it's 42v for a 36v Li-Ion battery)
but I’ll will check first thing in morning and post a video if I can if not I’ll post on YouTube
No video needed, you simply post the voltage numbers you get. (I don't intend to spend time watching a video just to see them

).
The test to do is literally just measuring the voltage of your battery while the system is on but stopped, then measuring it while riding (perhaps by taping the meter to the handlebars and the leads to the battery wires), and remembering or writing down the voltage it reads just before the cutout, and the voltage it reads during the cutout, and the voltage it reads after the cutout when motor operation resumes.
The reason for this test is to see if the battery voltage is dropping below a critical point and causing the controller or battery to stop working. If the voltage does not change between the last three readings, it isn't the battery voltage causing it.