Hi, I am working on a project that requires a 250A ESC to power a Turnigy RotoMax 150CC 190A Brushless motor.

I have attached the pics of ESC and motor below.
ESC product page : https://hobbyking.com/en_us/turnigy-dlux-250a-hv-14s-60v-esc.html
Motor : https://hobbyking.com/en_us/turnigy-rotomax-150cc-size-brushless-outrunner-motor.html

I am not able to program the ESC with my Tx, nor am I able to get the motor spinning using Tx (flysky ct6b). I tested a servo at the Rx side and its working properly. So I decided to give the ESC a PWM signal with an arduino by using a 10K POT with it. So by rotating the pot knob I can reduce or increase the PWM duty cycle (similar what a typical Tx does).

After power-on I get the startup beeps and then I am able to spin the motor. But here comes the main issue: The motor spins only for like 3-4 secs and then stops spinning. After which I have to decrease the throttle (i.e. lowering PWM duty cycle) and then increase again after which it again starts to spin again for 3-4 secs and then stops again. I also tested the ESC with a smaller "regular" brushless motor but the problem persists.

Initially I had hooked the ESC to 12V, 30AMP power supply. Then I hooked it to 4200mAH, 6s 22.2V Lipo and the same story. In past I have used 20-30Amp ESCs and usual brusheless quad motors but I have never used such monster ESCs and motors before. Can someone help me? Where I might be going wrong?

-Regards