Thank you very much for the additional information.
I can't tell the pixels because there is no ruler on the view and i have found that using a ruler on my display is not accurate
Place one node in the upper left corner of your view port and another node in the lower right corner of your view port. Now use your nodes' coordinates to calculate the size of the view port.
Print settings are [...], i don't see how to set or view margins.
What about poster rows and columns on tab "General" of yEd's print settings? These are very important.
Margins are specified in your printer's native print settings and thus it depends on your printer model where to find them. Usually, they are specified in the dialog where you specify the paper size.
If I use 'Automatic' in View Only, it does not change anything.
That is very strange. Does your printer offer "print to file"? If so, is the resulting document a PostScript (*.ps) or PDF (*.pdf) file? In this case, please consider uploading the file printout here. (See How to upload files to yEd Q&A? for instructions on uploading files here.)
If there were a way to (1) add a page break or (2) adjust the zoom by a user defined value then that would work for me.
Only through clever use of the "Clip Area" and "Scaling" options in yEd's print settings.