you mean it's long to reboot the Wii to launch the Wii in GameCube Mode ?
or do you mean it launch the gameCube mode, then it's long to do anything, then the Wii reboots to System menu/HBC ?
If it's the former:
I guess even if it's long to boot the game, but it still work, then it's fine.
So, it should be the second problem.
If it's the later:
- usually, DIOS MIOS switch off the Wii if something goes wrong, it doesn't reboot the console.
- Try reinstalling BC V6 and DIOS MIOS v2.10
- Connect the drive in port 0 (if port 0 is not detected after few seconds, it tried port1. So connect it in port0 will speed the HDD detection)
- Do you see the DIOS MIOS Splash screen or not at all ?
- If there's no Splash screen it means DIOS MIOS couldn't mount the drive/partition.
- If there's a splash screen but doesn't work, there's usually an error message displayed by DM which help determine the problem.
- Verify that your drive is 512Byte per sector, not 4096 (at least usbloaderGX 1213+ has a HDD and partition format/type detection, I don't know if other loaders have too).