Owner guaranteed financing

[Jose Rodriguez]

I was wondering if anyone has had any experience in guaranteeing a loan for a SFR tenant?
I have 4 properties and would like to be able to sell one house to a tenant with a lease option contract. After reading some of the templates and getting feedback from real estate agents, I found that usually the burden of qualifying for a mortgage is put on the tenant. If they don't qualify they end up losing their deposit. While that makes perfect sense and protects the investor, it leaves little choice for people with not so great credit, that can otherwise afford to make the payments.
I read another post for seller financing but what I'm interested is in helping the tenant qualify for the mortgage, and if necessary, guaranteeing the payment in case they default. I also have existing mortgages on these properties that would need to be paid off upon the sale.

The easy answer would be for me to sell the property in the open market, but it would be great if I can help my tenant become a property owner at some point. Is there any mortgage program that allows me, as the property owner to guarantee the loan in case the tenant doesn't qualify? if so, can I put a lien on the new mortgage for a certain amount to safeguard my interest?

Any ideas or comments are greatly appreciated.
Thanks,
Jose