What's the place worth? If you can get $120k out of selling it, then your return is $6k/120k or roughly 5%. That's extremely mediocre for a risky/illiquid asset like a townhome (what happens when the HOA assesses $15k to fix the driveways?)
Figure out your expenses, first:
-Mortgage, taxes, insurance. That should be easy, it's on your mortgage statement every month.
-HOA, if any. Since it's a townhouse, I assume that you have one. Have you looked at the reserve study lately? If you don't know what that is or the HOA doesn't have one, run now to the hardware store to get a for sale sign.
-Management. Most property managers charge in the ballpark of 10%. "But I manage it myself!" you say. That's great, but that's something you need to expense as well, because managing the place is a job and it will cost you time and effort to do. So for the sake of analysis, use 10% of your gross rent for this expense.
-Vacancy. Sooner or later you'll have tenants move out before others are ready to move in, or have to evict someone who doesn't pay. It happens. You *might* never have a problem or a vacancy, but you should still assume 5% of gross rents will be lost to this expense.
-Maintenance. If your HOA maintains the outside of the property, use 5% of gross rents. If not, use 10%. Carpet, paint, clogged toilets, etc, etc.
-CapEx. If HOA maintains outside, use 5% of gross rents. Otherwise 10%. This is money you set aside for anticipated costs (new furnace, new roof, new dishwasher) that are infrequent but expensive.
Are you still cashflowing? If so, awesome. You have a halfway decent rental - *if* you don't have a ton of capital tied up in it. If you have $120 sitting around earning a couple hundred bucks a month, on the other hand, you're shooting yourself in the foot holding onto the place.
-W