The unit has 4 furnaces and 4 AC units that are nearing the end of their lives and am trying to decide if I should keep it or sell due to the large capital expenditure coming in the near future.

.), management fees, capital expenditures (roof, driveway, flooring, etc.), utilities, insurance, landscaping, and everything else.My short-term rental earns enough in three months to cover all my expenses so the rest is my net income.

Just a few reactions.You have $300/year for repairs and capital expenditures. 

A SIMPLE Guide to Calculating CAPEXSO MANY INVESTORS CHOOSE TO IGNORE CAPITAL EXPENDITURES BUT I 100% AFFECTS YOUR INVESTMENT RETURN.There is a clearly defined way to come up with a multiplier you can use across your properties.

@Eman Yazdchi, I had maintenance (regular) and capital expenditures (bigger ticket items like roof, A/C) as separate, but I get what you're saying. 

How do you all handle inspections on properties that have the possibility of foundation issues, mold, or bigger capitol expenditures?

Although, for the majority of tax payers, with QIP expenditures, this is materially how it would apply.

Spent about $50k in upgrades mainly external capital expenditures (yard, privacy fence, dirt work, drainage, rain gutters, etc.), rented property on upper-end of projections, and am cash flowing off rental income on 2/3 units while living rent-free in the third .

"They say" to factor about 5% for maintenance and another 5% for Capital Expenditures, but 5% of what?

There is no budget to save for capital expenditures, like replacements to a roof or HVAC.