G'day Mate,
Sounds lean, be aware, early in the morning, the air is cooler & so it is more dense, so the motor can be run slightly leaner, as the day warms up, your mixture may need to be richened, a couple of clicks, to allow for the air becoming less dense.
The best test is, run your motor up to WOT, & hold the plane nose up at 45 Degrees, the engine should pick up revs slightly, if it doesn't, it is too lean, & needs a couple of clicks richer, & try again.
Don't worry about it not sounding like it is screaming its **** off, if it won't fly at this setting, you need a bigger motor.