I am not licensed to practice law in your state.
These comments are made for educational purposes only and do not constitute legal advice. No attorney-client relationship exists between us.
The statute of limitations for a written contract is 6 years and 3 years on oral contracts. Unfortunately, you have lost your chance to sue. If you can get him to admit he owes the debt, you might be able to re-start the calendar for another 3 years.