I know of the obvious expenses like tax, insurance, property management, utilities, repairs, vacancy, and mortgage.

After doing a quick and dirty analysis: 600*8(units)=48004800*12(months)=5760057600*.5(vacancies, expenses, taxes, insurance,etc.)= $28,800 NOIWith the numbers looking like this I was thinking about keeping this one but have no idea about how to finance it.

Very low vacancy rates, quiet neighborhood and quality residents are making things relatively simple right now.  

It required some renovations due to deferred maintenance / vacancy, but is now up and running as a rental property.

Maybe you immediately generate a vacancy if you do.

Another poster was saying that for a HELOC they assumed you drew out the full amount, for example.I would think that even if a lender used (PITI / (75%*rent)) for a new property they would still use actuals from existing ones.If you think about it, if the rental truly is cash flow positive (after all expenses, vacancy, and capital, NOT just rent > PITI) then owning the rental improves your personal income statement.

I still have yet to cut my teeth on filling a vacancy, but hey that is a good thing, I think it means I picked a good property.Looking forward to learning from you all,Mike

If the tenant is a D class tenant that is undesirable and I think I want to move them out, then I am not going to show a lot of rent increases from year one to year two, because I know once I start enforcing the rules, these people are going to leave and I am going to have vacancies and have to clean up those units and bring new people in.

Even if you manage this yourself, it takes time and effort to find renters and manage 4 units.If I assume 10% vacancy and 10% management fees, (may be high, but better to be conservative), I get net monthly cash flow of $561 and internal rate of return at 39%.Can you get and keep this rented?

When I visited and said I was looking to keep it as a rental at the same rent, the tenant was very happy and told me, "please buy this house".)Monthly expenses/reserves: $591 --> taxes, insurance, vacancy, maintenance, property management.