Seems tight, BUT it depends on what are the other expenses.
For that rent price, do you pay the utilities, landscaping, other regular fees?
When are the big ticket maintenance items due?(windows, roof, pavement, etc) You should count their amortised price as a monthly expense.
Check for guidelines as for expected vacancies in your parts. I use 5 percent (1 month every 2 years) and add it as a monthly expense.
Is there still positive cashflow? Then the idea is not stupid. There may be bumps in the way (leaking faucets, bumps, nicks and holes in drywall) so for it to be a *good* idea, you would need a better rent to mortgage ratio.