Just try to autoboot a game for start, use wii bootme to set the game to autoboot. Then try to autoboot your mario Kart without doing anything to it except patching it to autoboot. If the Mario Kart will not boot, but other games do, then your Mario Kart iso is no good, dump it again (somehow). You should not need to do anything to the Mario Kart iso except replace the wad in the installer partition, patch the game to autoboot, and patch the installer partition to ios36 or 250. You don't need to save the crypted partition and then import it, this does not fakesign the crypted partition. But you can't do anything if you can't get Mario Kart to boot.