A9o OOP is not a great hand to play if you do not know if CO folds. You did not raise enough to scare him out. if you figure that with any raise big enough to scare CO out (250 would be a good amount IMO) you will be pot-commited with your stack - then you may as well push. our FE is much greater and you eliminate your positional disadvantage.

However - your M is about 9, you just paid the blinds - I'd wait for a better hand.