i found this in a read me file in menu version 1.9...
Installation: Copy NEON64.v64 and NEON64MF.v64 to where your N64 rom
images are. In the Neo2 Pro Manager on your PC, set the boot type to
"TypeA-2: N64 U2", set the BIOS Path A-2 to the NEON64.v64 image, then
click "Burn" to set the menu in the N64 Myth menu flash.
so reading that i guess i forgot to flash neon64mf with neon64 and mario kart, so i was kinda right 1st time around lol