Oh, okay. 30% throttle in the TX does not mean 30% throttle out of the ESC in that case. In the Castle ESC setup for set rpm gov mode, where you had to input your three RPM settings, there is a little info button right next to each RPM entry. Click it to see what that RPM translates into in terms of throttle amount.
My guess is you are actually fine on throttle output from the ESC. I do not believe that the heli would even hover if it were truly running that motor at 30% throttle output to the motor.
IF you have an optical thermometer (temperature gun) bring it with you next time and get some readings. And try a flight, even just hovering, at stunt1 or stunt2 (double check your pitch curves), just to see if it improves or worsens your heat issue.
I'm guessing everything is fine. Like I said, 600 and 700 motors get pretty hot. I can usually touch the can once or twice but not a third time without chanting some "hooosaaaah" and imagining people walking on hot coals.
Once you have a base line you can play with some of the settings in the castle ESC setup on the later tabs where it has PWM frequency, timing/advance setting, etc. Lowering timing/advance will usually result in cooler running, but also a loss of some power (probably will not be noticable if you're hovering and sport flying so give it a try). PWM frequency usually doesn't affect motor temp, but it can affect ESC temp. Lower PWM freq will lower ESC temp, but may have negative effects on motor behavior. As always, make one change at a time and do a test flight or two to see if the changes help or hurt. And save backups of your settings so you can revert back easily if you don't like a change you made.
