AJ,
The Motiv must accepts patch changes 0-127 (or hexadecimal 00-7F). In MIDI there is a strict distinction between databytes and statusbytes. Databytes are always 0-127, statusbytes are always 128-255. 128 would be the statusbyte for note-off. A lot of synths specify their patches and notenumbers in the manuals as 1-128 but that's just the difference of computer language (0-127) and human language (1-128). Computers call the first 0, humans call the first 1. If the guitar harmonics is 32 on a scale of 1-128 then that is hexadecimal value 1F and that is the correct GM patchnumber for guitar harmonics. Wether you call this 32 on a scale of 1-128 or 31 on a scale of 0-127 or XXXII in roman numbers, it will stil be hexadecimal value 1F. In OMB and most other software the notation is 0-127 so just use any GM patch lists that goes 0-127 and use that numbers if your editing for any GM bank including the one on your Motive.
So what I'm trying to say is that if you play GM midi files or when you play styles with OMB in GM mode, it should sound allright on your Motiv GM bank. If it doesn't there must be some other problem.
JM