You might be a hair rich still, but don't mess with it any more. Fly the plane. You will find that on approach you might be idling for a minute or more, particularly with a trainer. One trick to avoid deadsticks on approach is to make sure you've had it at full throttle for a few seconds before you start your glide. This will keep the engine warm. Also, when you drop your throttle for the glide, raise it back up slightly. You can drop it back when you're just about on the field.

Brad