There are a few ways to correct this but I'm not sure if that particular ESC allows some of them. The ESC is losing sync with the motor. You can increase timing which is what I normally do, up to the 20 to 30 degree range, but I would assume that ESC doesn't allow you to go that high which is creating the issue. You can also put a delay in the throttle channel on the radio which electronically does what you're doing when you move the stick slowly, assuming your radio has that feature,.. or use a setting in the speed control to slow down the throttle travel, or, use a smaller prop.
Originally Posted by kerwin50
I have an A30/28 on a 3DHS Edge 41 that squeals under burst of power and at WOT if I don't move the throttle stick real slow.
I'm using a hobbywing pentium ESC with the timing set on high. My prop is an APC 11/5.5