It is possible. This is how you do it for NSMB. Your game may be similar.
[GUIDE] Convert NSMB PAL save to NTSC
Short guide on how to convert a PAL save to NTSC.
***BACKUP YOUR SAVES FIRST, DON'T COME COMPLAINING IF YOU SCREW IT UP AND LOSE YOUR SAVE.***
All you need is Savegame Manager here and a hex editor (Hex Editor Neo is free here).
1. Make sure you have a game save for your NTSC-U version. Then open Savegame Manager and select "extract" and "SD".
2. Find your NSMBW saves (should be listed twice, one for each region) and extract them.
3. You can now delete the PAL save file (it's the one that says "Play Mario with your friends!," while the NTSC-U says "A new Mario adventure!". DO NOT DELETE THE NTSC-U SAVEGAME OR YOU WILL GET THE -106 ERROR WHEN YOU TRY TO REINSTALL IT! If you do by accident, just run the NTSC-U game and create a new one.
4. Now take your SD card and put it in your computer.
5. In the root of your SD card you will find the "savegames" folder with two more folders in it. The one that ends with "45" is NTSC-U and the one that ends with "50" is your PAL save. Open the PAL folder (00010000534d4e50) and open "wiimj2d.sav" with your hex editor.
6. The very first thing you should see on the text side is "SMNP". Change the "P" to "E" (yes it is case sensitive) and save.
7. Copy the edited "wiimj2d.sav" to your NTSC-U folder (00010000534d4e45), and delete the PAL folder.
8. Now insert the SD card back into your Wii and launch Savegame Manager.
9. This time select "install" then "SD" and install your NSMBW save.