New deal analysis rookie investor

[Account Closed]

This is my first deal and I am looking to make sure that I do it right.

I am looking at a St Louis really old 4 plex which was recently updated in a C area. (New roof, tuck point and plumbing stacks). The heaters and furnace are old. I am yet to get it inspected so this assumes that inspection will go through.

I put it an offer for $120k ( with closing and some rehab another 14k would be needed). At 25% I will be all in at $44k. 

Here are my expense numbers (all monthly) Rentees pay utilities.

1) PITI - 483

2) Insurance - 120

3) Water and Sewer - 220

4) Repairs - 220

5) Mowing - 25

6) Vacancy and Capex - 220 (110 each)

7) Garbage - 56

8) Management - 220

9) Taxes - 81

The rent is expected to be 550 per door or 2200 all in. The CF comes to about 554. 

My main concern is CapEX. I feel that 5% or 110 is on the low side. How to in general estimate it? Have I missed any other cost item?

Also would love to hear thoughts from experienced folks here esp from St Louis, are these decent numbers?. I want to make sure I do it right.