brute force is a no go

[frequency]

i ripped out the demo movies and other useless junk to make it fit onto a dvd-r. then i got the default.xbe file and changed the string: E8CAFDFFFF85C07D to E8CAFDFFFF85C0EB to bypass the media check. the file size of the iso is 4,317.25MB. but when i loaded the burned disc onto my xbox it says no disc on the evox menu at the top right corner. my bios is 4976.02. any suggestions as to why this is happening?