C.V.
You must stop the cycle. So he's running around, happy and smiling, and starts trying to bite. You need to grab him. Stop him physically, and very FIRMLY say "NO! NO! We don't bite. NO!" Hold his gaze long enough for him to know that it's NOT funtime anymore before letting him go. If he cries, don't try to comfort him. He was wrong and needs to remember that.
Do it again and again. If needed, remove him completely from all attention.
ETA: FWIW, I'm an advocate of biting back. It's worked in my family. My kids bit maybe two times each, and were bitten back by either my mom or me. They stopped. I know it's not for everyone, but it worked for us.