Expert: Ken Myers - 6/16/2009

Question
I have a problem with my 480 outrunner. It has started to act very erratic. Sometimes when I advance the throttle, the motor will try to turn backwards. Sometimes it will switch back and forth and then stop. It seems to work fine without a prop on it. I changed the output shaft thinking it was bent. I have replaced the ESC unit.

Answer
Hi Eugene,

It is very normal for a brushless outrunner to "hunt" for the direction it should be running, based on what the ESC is telling it.  Sometimes, a certain brand ESC does not work very well with certain outrunners, but since you replaced the ESC, that may not be the problem, unless you replaced it with the same brand ESC.  The motors themselves are so simple, they are usually not the problem, unless there is a loose or broken connection.  Also, there can be a loose or partially broken connection due to a bad solder job in the connectors between the ESC and motor.  You might check that as well.  Be sure to also try a different brand of ESC from the one you used initially.

Good Luck,
Ken