How long is the statue of limitation for an old business partner/founder to sue?

Do you have a written partnership agreement?  If so, the limitations perios would be three years. You should consult with a business attorney in your local area.

There are a number of different statutes of limitation that could apply here.   There are 1 year, 2 year, 3 year and 4 year statutes of limitation.  It all depends upon the cause of action.  What is more important than the time period is the date that the applicable statute starts to run.   Different events trigger the start of each Statute.   Generally speaking the trigger date is the date when something that should happen does not happen and the other side knows it. You also seem to have some good issues regarding his abandonment of his role in the business as well as your claims to full ownership.  One question is whether you have a written or oral agreement and what are the terms of that agreement? Based upon this short version of the story, it appears that you have several good defenses to any action by this individual seeking to share in the profits of this business. What you need is a business litigation who can respond in the best way to any claims by this other individual and defend your position.   I have 38 years of experience in this are of law and you are welcome to contact my office at (909) 395-0909   Robert Spitz