[drcoastline]

There is not nearly enough information to make the decision.

First there is no such thing as ironclad. You will be holding a note with a mortgage. You will be subject to all the laws as any lender and will be required to foreclose according to law.

To start what kind of figures are we talking about? What is the buyers credit score? What is buyers debt ratio? What happens in two years when the note is due and balloons? Especially if he cannot refi the balloon amount? Are you willing to hold the balance for an additional time frame? Are you prepared to accept a lower interest rate and an extended time if he defaults? What are the terms of the second? is it based on a thirty year term with a two year balloon P&I or just interest? Are values going up, down or holding in your area? What does your financial picture look like? Can you afford the foreclosure battle and/or are you willing to give up part of your 70% to fight in court?

If you are comfortable walking with 70% it may be worth the risk. You will be in a second position as a lender. If he defaults on you alone it will be very costly for you to foreclose/collect.