Will this work even if your Wii can't run Super Mario Galaxy? I have no idea what kind of modchip my Wii has.
Most likely not. Remember the requirements are:
1)For non-japanese wii's, having your wii updated to the 3.1 level firmware prior to playing the game. Check your wii's configuration menu to see if your wii is 3.1u (USA NTSC-U) or 3.1e (Europe PAL). If it's not at 3.1, connect your wii to the internet or try to find a game that will upgrade it (for PAL, you may try wii chess or donkey kong jet racer). But always check you indeed have a 3.1 wii.
2)For non-japanese wii's: to have autoregion enabled in your chip or, alternatively, use regionfrii to set the iso of the game to your region prior to burning it. Either single one or both options work. When in doubt, use regionfrii.
3)For wiikey users, to have at least 1.9g revision of their chip's firmware (i.e. can play mario galaxy).
4)To allow the update of this game to run (totally or partially). If you never let the update run at all because you brick-block all your copies, you'll never be able to play this game.
5)Find a good combination of burner/media that will produce a dual layer recording that your wii likes. This is a bit of trial and error and you should try at least two different brands of media and two burners before you even start suspecting your problem maybe something else. Recommended recording speeds are in general 2.4x and 4x. Recommended media brands in general are TDK, Memorex and Verbatim. Recommended burners in general are: most recent ones less than a year old, otherwise pioneer and non-laptop burners, in general.
6)For owners of wii's with chips other than wiikey, the dual layer burnt backup of this game may be a lot harder to run than for others. You should also be using DVD+R DL media (instead of DVD-R) and set the layerbreak in your recording software to 2084960. (i.e. on imgburn tools->settings->Write->Layer Break->User specified and type 2084960)
If you follow these directions, you have a very high chance of being able to play this game fully, without tricks or swaps, with your full dvd9 backup copy of ssbb. The only problem is that it will leave you with duplicated news and weather channels on non-japanese wii's, unless you resort to the 15% trick, which is explained elsewhere.