I couldn't really comment comprehensively on this because there are several facts which aren't in your question. Given the issues you've raised, I wouldn't suggest that you do so on Avvo. A few questions which come to mind are, why did you transfer title to him? Did he make payments on the motorcycle? It sounds like at some point, you agreed to put his name on the loan, have him make the payments and to have the vehicle insured? A lot of factors would go into this. Was this a gift or were you just helping him out, for example? What is the vehicle worth? You could have a small claims or civil case although without knowing the additional facts here, I could not make any further suggestions. You could speak with a general practitioner or civil litigator as to how to proceed.
Ms. Johns is a lawyer although she is not your lawyer unless you have consulted with her and signed a fee or letter agreement confirming her representation. This post does not constitute legal advice and no attorney client relationship results.
If the motorcycle is in your name, and registered to you, you are the legal owner, subject to the lien from the lender.
You will probably have to file a lawsuit to regain possession or the value of the motorcycle.
You could let the lender re-possess, but that might have a negative impact on your credit, at least. Probably would result in you being sued for whatever is owed.
You might be able to sue in small claims as long as the value is under 10,000.
Filing the suit might be enough for your ex to get on the ball.