I need to know FOR SURE how to tell if mt brushless motor is bad b4 I hook it up to my new esc. I put the ezrun 30a 9T combo on my buddys Peade cause we wanted to c what it woul do. It was doin better that 50 for about 40 yds Then....u guessed it. Poped tha cap on tha controller. To heavy a truck 4 such a small combo. I got a Sv2 but b4 I hhok it up to the 4300kv HobbyWing, I need to know that it wasnt the HobbyWing that popped the cap in tha 1st place. How do I check this? Im outta hobby money til my wife sees this thing kick up some dirt. Frying the new Castle would b SUCH a horrible thing.

What about speaking english? O.O

I take it you are talking about the finned can hobbywing 9t??If so , yeah that is actually a 380 sized rotor and coil assembly NOT 540 size to allow for the fins. so you are right in supposing that the truck was too heavy unless you geared it way down especially with the 30 a speedo...I am betting you just toasted the 30 A speedo and you could try the castle speedo with no issues.But i would next be looking for a bit better motor to run than that 9T

http://http://www.nitrorcx.com/96m23-car-3650-3930.html

you can get this for under 30.00, and it is WAY better than your current motor.It wil deliver more low end torque than the 9T and run much cooler.