Motors run full whenever above idle

I got out an old APM controller and was going to put it in use. Everything seems to work: Radio calibration, ESC calibration. The motors run up smoothly when I use a “servo tester”.

BUT… when I connect the motors to the controller and ARM them, they spin normally (and slowly). But when I raise the throttle just a little bit, the motors instantly go to full speed. The SERVO OUTPUT graphs on Mission Planner indicate the same thing.

Again, I have calibrated the ESCs, and did a RADIO calibration as well. In the CONFIG section, I set the TRIMS all to 1500 (they were all zero) but that didn’t help. The Full parameter List shows that the channel mins are all close to 1000 and the channel maxes are all close to 2000. Does someone have an idea what might be causing this problem?

You need to do esc calibration again and remove any trims, throttle curves, etc… on your transmitter

Hey there. How many times should this be done?

One time if you don’t change anything on your craft. Check the first time setup in ardupilot.org to get instructions, others can help you too

Can you please attach the bin logs?

check if the motors are connected correctly, motor numbering