(06 Jan 2015, 4:38 pm)Robert wrote The 843 does continue onto Leeds but even to York you're going to be on a bus for a long time. The X12 and X93 are both reasonably long too. I wouldnt be able to do what you're planning myself.
Two hours thirteen mins on the X93! Something like one hour forty five on the 843. I wouldn't mind that though, as it is a new operator (think it might be Transdev?) and apparently the route is pretty scenic.
I've heard EYMS' X46/X47 between York and Hull is quite a beautiful run, and it's two hours exactly.