Older units will use more resources (gas/electric/water), which is a cost only you will incur.

-Roof ( find out when the roof was placed, the condition) - Electric/ Gas ( find out metering situation) if they are not separately metered that will cut into the cash flow. - Windows( for multi-unit properties if there are a lot of windows that need to be replaced this can costly.) - Overall repairs needed In conclusion, research the area and find a good property manager or inspector and make sure they look more into the things above and anything you know of that is a high-cost repair! 

Property DetailsCurrent Mortgage Balance: $113kCurrent Estimated Home Value: $180kYears Bought: 2013Interest: 30-year fixed 3.99% (No PMI using special loan program for just 15% down)Analysis: Income Current Lump $50k Principal Payment Paid Off Mortgage Rental Income $ 1,500.00 $ 1,500.00 $ 1,500.00 Laundry Income $ - $ - $ - Storage Income $ - $ - $ - Miscellaneous Income $ - $ - $ - TOTAL Monthly Income $ 1,500.00 $ 1,500.00 $ 1,500.00       Expenses       Water/Sewer $ - $ - $ - Garbage $ - $ - $ - Electric $ - $ - $ - Gas $ - $ - $ - HOA $ 240.00 $ 240.00 $ 240.00 Lawn/Snow $ - $ - $ - Vacancy $ 150.00 $ 150.00 $ 150.00 Repairs $ 15.00 $ 15.00 $ 15.00 CapEx (Replacing Things) $ 125.00 $ 125.00 $ 125.00 Property Management $ 150.00 $ 150.00 $ 150.00 PITI $ 778.67 $ 475.15 $ 180.00 Other Expenses $ - $ - $ - Total Monthly Expenses $ 1,458.67 $ 1,155.15 $ 860.00       Cash Flow       Total Monthly Income $ 1,500.00 $ 1,500.00 $ 1,500.00 Total Monthly Expenses $ 1,458.67 $ 1,155.15 $ 860.00 Total Monthly Cash Flow $ 41.33 $ 344.85 $ 640.00 Total Annual Cash Flow $ 495.96 $ 4,138.20 $ 7,680.00       Cash on Cash Return       Down Payment $ 30,000.00 $ 30,000.00 $ 30,000.00 Closing Costs $ 2,000.00 $ 2,000.00 $ 2,000.00 Addition Lump Principal Payment $ - $ 50,000.00 $ 115,000.00 Miscellaneous Initial Costs $ 3,000.00 $ 3,000.00 $ 3,000.00 Total Investment $ 35,000.00 $ 85,000.00 $ 150,000.00 Cash on Cash Return 1% 5% 5%Any helpful insight and/or constructive criticism on the math and assumptions on this analysis would be greatly appreciated.

I would also check the state of the electrical wiring. 

How do I make sure the water and electric bill are all in their names?

Once you’ve read enough T12s and understand avg expenses per door whatever market you’re in, you will better understand your proforma and how the property would operate You can simply take out the perceived capex line items, then categorize as Capex/Major Repairs (roof replacement or repair, re-plumbing, repave parking lots, ac, electrical, interior & exterior Reno) Expenses (taxes, insurance, service contracts, management, utilities- wst, turnover, legal, maintenance, G&A, payroll) Now take the income minus expenses.

All large cap ex items have been replaced (plumbing, electric, roof, A/C, windows, appliances).

Check with your municipal office to see if you can put up a electric cattle fence.

Did a medium rehab to both of the units which included work on the bathrooms, kitchens, electrical, plumbing, flooring, paint, hvac, etc.

Nor does it look like you have accounted for the electrical.