It is very hard to admit that you don't know something. Talking is not teaching. Instructors do not motivate their students. They create an environment in which students choose to motivate themselves. Teach with passion.
Enthusiasm generates enthusiasm.
Tell students why they should learn something, the benefits to be derived from learning it, and how they can use it immediately in their lives. Believe in yourself as a teacher and your students will believe in you. Be the best you can be today when you teach and then be better tomorrow. Always find positive things to say to your students in person and in writing. Think of ten different ways to say thank you and use them in every teleclass.