chasing

Question
my dog chases atv bites at tires does not chase anything else need help stopping this behavior

Answer
First off, you'll need to keep him on leash or otherwise physically contained so that he doesn't have the opportunity to chase ATVs.  

The next thing is to teach him "Leave It".  Here's an article on teaching basic "Leave It":
http://www.clickersolutions.com/articles/2001/leaveit.htm

This article discusses teaching "Leave It" with live things, but the technique would apply in your situation as well:
http://www.clickersolutions.com/articles/2001b/leaveit.htm

Chasing is generally a self-reinforcing behavior, so it will take time, consistency, and patience.

Good luck!