Triplex Analysis for a noobie

[Ian E.]

I am looking at purchasing a mid-1980s Triplex (2/1 for each door) for $120k.  It is currently at 100% occupancy at $675 per month.

Monthly rent - $2,025

Taxes - $145

Insurance - $125

Management - $202.5

Maintenance - $202.5

Vacancy - $202.5

Total Expenses - $877.5

Down Payment - $40k

Debt Service ($80k @ 20 years) - $472.5

Cash Flow - $675 ($225 per door)

This is my first property so I want to make sure I am doing everything right. However, the math seems like a deal.  I am currently stationed overseas so I will not be able to actually conduct a walkthrough.  What am I missing?