I'm right there with you on the potty training woes! Hercules is 5 1/2 months and sounds a lot like Maximus (which is a great name!).
Some days he does great and other days he's going all over the place. We're training him to go outside though. I've read that yorkies are extremely hard to potty train. It just takes a lot of patience, persistence, and good carpet cleaner!
I'd like to hear if any other yorkie owners with more experience have more light to shed on the topic too.
Oh, and welcome to yorkie talk, there are definitely lots of nice and sincere people out there. I love this place and don't know what I'd do without it!!