Help! Need advice in regards to my next steps in investing

[John Wulf]

This is my first official post to the forums, but am really curious on what some of you might recommend for me on my next steps moving forward with my real estate investing. Here is where I'm currently at:

I currently have 4 rental properties which I have taken advantage of the low interest rates and have them each on a 30 year fixed mortgage (each at below 4%). They are each cash flow positive, and have never been vacant. 

I have a line of credit for $150,000 that I use to buy flips, but currently just bought a house for $150,000 cash and am in the process of doing a cash out refinance. So that will be 5 rentals currently owned.

Why I'm here, and why I'm asking all of your smart advice is that I just got notice on one of my rentals that the tenant will be moving out at the end of November. This is a house I thought about selling already because I actually lived in the house for 2 of the last 5 years as my personal home, so I would be able to sell the house and be sheltered from any capital gains tax.

With that said, I also should be able to rent the house quickly with a positive income of around $500/month after all expenses... or I could sell the house and take home roughly $130,000 in equity. 

My question for all of you is should I pay off one of my rentals (balance only being $72,000) and buy another rental property with the balance of the equity? Should I hang on to the house since it's producing solid monthly return? Should I use the equity towards flipping houses and not use my LOC?

Financing is just getting tighter and tighter...

I'm just in a situation that I'm not sure what to do, and would want to know each of your opinions. I hate selling the house on such low interest financing, but I also know I have the advantage of not having to pay taxes on any of the gains from the sell. 

Any thoughts? Advice? Anything would be appreciated!