The mesh definitely looks too tight, try the "paper method" for the correct mesh.
I do mine by eye, just so that the spurs teeth "rock" inside the pinion.
Is your battery up to the job?
If you have low spec lipo, it might not be providing enough power for the motor.
This causes cogging on initial take-off.
Is your brushless esc set up correctly?
If your "punch" is set too high this can have the same effect as the last point.
If you have the programming card for the ESC, it's a 2 min job to sort it.
Just drop it down a touch.
Definitely get your slipper set right though, that's the only problem I have had.
Sort that, and you should be good to go!
Cheers
KingPin