||Not too happy with the Tekin Pro4 motors so far. I have both a 3300KV and 4000KV with both motors failing with broken magnets within 1 month of purchase. Temps were kept below 180F and jumps were no higher than 3 feet on dirt. So far over $500 invested in the RX8 plus two Pro4 motors.
I bought this sytem to be more durable and have longer run time than the stock motors before overheating (Traxxas Slash 4x4, Velenion 3500KV on 3S). I was not looking for better performance, the stock power system performance was fine with me. So far none of those goals are met. Bottom line is the motors are not holding up or running at lower temps than stock (so I did not get any extended run time vs. stock before overheating). By comparisoin, the stock motors were lasting 6-9 months with the exact same usage before needing a rebuild.
Tekin warranty repair was immediate for the first motor failure. They replaced the broken rotor and shipped the unit back to me within a few days. However the repaired motor was not smooth when tuned by hand. The second motor is in the process of being returned now.
If this continues, I plan to upgrade the 2650 KV T8 buggy motor and still only run on 3S. I have another Slash 4x4 with a Castle Mamba Monster and 2200KV motor that has been bullet proof for 2 years runing mostly 4S and some 6S with no issues.
I know others have had good luck with the Tekin Pro4 motors, but not me.