OK. Here goes. I am building an "outlaw" pinewood derby car for a leaders race. I am going to use a ducted fan. Powered with a 7.4 2s lipo. Originally I had a 30A esc and was using a servo tester to supply the signal to the ESC to spin the motor.

It had worked. But now it does not. When I power it up, I get the "do do do" tone (progressively higher pitched). Then 2 short beeps (2s lipo). Then one long beep.

But when I turn the dial on the tester, the motor just jerks a little and does not spin like it used to.

Here's the components:

Holy Stone 2-In-1 Battery Charger and 2Pcs 7.4V 2000mAh Rechargeable Li-Po RC Drone Batteries for HS300,HS400

YKS RC Servo Tester Multi 3CH ECS Consistency Speed Controler Power Channels CCPM Meter with Reverse Connection Protection

uxcell 30mm 6 Blades Ducted Fan EDF Unit Jet Engine with 7000KV Brushless Motor for RC Airplane

RioRand 30A Brushless Motor Speed Controller RC BEC ESC


So. What went wrong? Did I over heat the ESC?

I bought a different motor:

uxcell 64mm 5 Blades Ducted Fan EDF Unit Jet Engine with 4500KV 3S RC Brushless Motor for RC Airplane

That did not help. YES, I know these are cheap parts. But I only need them to last a little bit. I have a couple of cheap 40a ESC's on order to see if that helps.

I am open to all thoughts on the problem.

Thanks.