Q1) "the person i was suing died this month.will I be able to get my motorcycle back or will it cost me even more money to fight this in probate court."
A1) You can't just 'take' the motorcycle back. However, you can make a claim against his estate for the unpaid amount.
Q2) "what would happen if i don't get the bike back and don't sign the title over to his family"
A2) No one knows, since we have NO idea what the sales terms were, amount paid, amount promised, title status, etc.
My suggestion, contact the family and offer a refund for the return of the bike.