Kitten biting

My 4 month old kitten continues to bite hands and arms. It is really hard to break him of it. 

I am at the point where I had to yell no and push him away.

How do I break him of this habit? I guess handing him a toy but then he drops the toy and chews on my arm.

When he bites you, you absolutely have to disengage. Pushing him away (or running away so he chases you, or any other kind of physical retaliation or further attention) is giving him exactly what he wants. He wants to play fight and wrestle with you, like you were another kitten. More than anything he wants to play. Once he learns that biting means play time is over and he gets no more attention, he will learn to play nice.

To start with, you need to stop all hand play now. Make sure all toys that you use to play with him (as opposed to toys he can kick and bite the hell out of) are wand toys - your hands need to be a long way from the action.

Any movements you make towards him with your hands need to be calm, slow and steady. If you move like prey, you can expect to be treated like prey If he does latch on to you, freeze until he lets go - 'prey' is no longer interesting once it's 'dead'.

Something else that can help is hissing at him - be as cat-like as you can in both sound and facial expression. Cats naturally understand that a hiss means 'back off'. It's an easy way to teach without traumatising. These articles have some good pointers too:-
http://www.thecatsite.com/a/playtime-aggression
http://www.thecatsite.com/a/the-dos-and-donts-of-cat-behavior-modification