Question about ownership and whether my ex can take my motorcycle behind my back

My ex is threatening to take back my motorcycle as a control method to further isolate me... it is currently not insured or registered that I know of. He took the plates, threatened to take it back after canceling the insurance.He bought it from a private seller (that I paid back but have no record of). The mail to and name on the front of the title is in his name, but he had me sign all signature placements as the owner on the back, and signed his name under seller to me, and signed it as sold to me for $500.Can he take it from me? via /r/motorcycles https://www.reddit.com/r/motorcycles/comments/czm22g/question_about_ownership_and_whether_my_ex_can/?utm_source=ifttt