Will try that Eddie but i have a feeling that the Roland messages are not generic, because i found this howto turn of parts on SC-55 and others.
Did not work for my SC-7.
Any of the 16 parts can be turned off using the part numbering given in Figure 3 (page 5).
Fig. 3. The SoundCanvas listens on all 16 MIDI channels. Use the sys-ex messages in this chart to turn off individual parts.
Part 1: F0 41 10 42 12 40 11 02 10 1D F7
Part 2: F0 41 10 42 12 40 12 02 10 1C F7
Part 3: F0 41 10 42 12 40 13 02 10 1B F7
Part 4: F0 41 10 42 12 40 14 02 10 1A F7
Part 5: F0 41 10 42 12 40 15 02 10 19 F7
Part 6: F0 41 10 42 12 40 16 02 10 18 F7
Part 7: F0 41 10 42 12 40 17 02 10 17 F7
Part 8: F0 41 10 42 12 40 18 02 10 16 F7
Part 9: F0 41 10 42 12 40 19 02 10 15 F7
Part 10: F0 41 10 42 12 40 10 02 10 1E F7
Part 11: F0 41 10 42 12 40 1A 02 10 14 F7
Part 12: F0 41 10 42 12 40 1B 02 10 13 F7
Part 13: F0 41 10 42 12 40 1C 02 10 12 F7
Part 14: F0 41 10 42 12 40 1D 02 10 11 F7
Part 15: F0 41 10 42 12 40 1E 02 10 10 F7
Part 16: F0 41 10 42 12 40 1F 02 10 0F F7
https://www.sweetwater.com/sweetcare/articles/depth-midi-functions-of-roland-sound-canvas/