Ya ha ha .. ok.. but seriously
I have found a few things out.. according to the help file you can fit 32 lines.. not so.. only 28 lines will show no matter what I do to them..
128 characters is a ridiculously low number when adding into account color codes for a pic.. but the actuall limit seems to vary from line to line. However most lines 127 was the limit, and a few it was 126.
System font as you may know counts the characters for every one differently, making its a real pain to try to organize and space right, since the system 'space' using the space bar is tiny.. using the Alt + 255 to make spaces does seem to help. They are nearly double the size of the space bar ones and therefore take up less of your limit of 128.
Im begging Ouka to rethink this .. as it stands.. many many rooms enjoy the convinence of adding pics to the motd.. however I would say for all practicality.. its not a good idea to attempt with Ouka severs.