Looking for rental property

[Willis Seng]

It seems like almost every investment property listed on this site is a good investment property. The latest one listed is a 4 plex for 149,900. Each unit rents for 1700 if i remember correctly. So... 4 units times 1700 is 6,800 which should cover a few months of mortgage and expenses am I right? If im doing my math right, wouldnt this be a great investment property? Maybe the neighborhood isnt great or maybe building is old. But 6,800/mo. minus expenses is gonna be crazy cashflow. It seems like every investment property listed is a great one. I think im doing something wrong here. I dont want to make the mistake of jumping into a property too quickly. Can someone enlighten me here?