First owner finance deal

[Paul A Christy]

Hi everyone, I found an owner willing to be the bank for me for 95% (only 5%down ) in a simple loan of 4.25 percent interest for 5 (maybe even 7 years) but then the balloon pops and I owe him the entire asking price. As is I would probably cash flow around 1-2 hundred on day one but it’s under market rent by 5 to 7 hundred a month (tenets are month to month ) and he has 4 garages that I could rent out there as well. Property is in good shape and in an EXCELLENT town. But my concern is when I have to refinance that it will not have gained 20 percent equity since I think it’s about 25-35 k over market rate (lessthan 5 percent of total)  or worse it will go down in value putting me in a pickle.. any advice please??