No one has been rude. You wrote everything is being bitten, then said his stall bars.
So is he biting "everything" or just the bars on stall?
If everything, you need to tell us what is going on when biting, for instance, grooming, tacking, or leading, or at feeding time, during turn out, or other horses and people? Is this happening all, most, or only some of the time?
How long have you had him and how much experience do you have with horses?
When you say "he is willing to run" what does that mean? You only run him? Or he is a racehorse, and that is what he does as a career?
What is he being fed, both grain and hay, is he turned out any, and does he have anything, if he is stalled, to alleviate boredom? Can he see or interact with other horses? Is he a gelding? What breed and age?
How old are you, and what experience do you have with horses, and if young, is there someone around with more experience? Where did this horse come from, is he new to you, or one that you have had for a while?
Any other information that you can throw in would help to figure out what is going on here.