Finally figured out the source of the signal which reset all tracks on many of my old sequences to R/L at the beginning of a song, even thought the saved assignment showed correctly when the motif was first powered up each time.  Since the reset sent the drummer’s click track channel out through the mains instead of just to him via asR, this was a bad thing.  The “Turn General MIDI System On” (F0 7E 7F 09 01 F7) at the beginning of most of the sequences seems to be the culprit.  When I delete the SYSX or at least remove the auto-send, the click track routing doesn’t reset.
Oh, I’m using Sonar 7, firewire to MOTU 828, with MIDI out to rack motif.
Am I setting myself up for another performance surprise, now that I’m no longer sending a SYSX?  (This omission set off some horrible things with the previous tone generator, and randomly.) Is there another SYSX code I should be using with the motif rack-XS?
Major show in 2 weeks, and it’s a fly-in so I need this wonderfully compact motif rack.  Otherwise I wouldn’t step on that stage without testing it at a smaller venue.

Perhaps this article will help (from the Clinician’s Corner in the SUPPORT area of this site):
A Short Tutorial: Creating Proper GM Files

..and although the article is about creating proper GM files, you may be able to gather much from it in terms of what data to expect to find when working with them.

Thank you! - These are the rules I’ve always followed.  I’ve always used that sysx string, or the one below, and left a blank measure at the beginning.  But there is one more result of using that GM reset - it reassigns the Channel Out assignments on the motif rack to L/R.  I can find no MIDI command to insert at the beginning of the song to direct the motif rack to restore the output back to Assigned Output L or R.

Now, there is another sysx string that doesn’t seem to reassign the outputs:  F0 41 10 42 12 40 1A 15 02 0F F7
Any idea why, and if this also accomplishes a reset of wheel, volume, etc?

I can find no MIDI command to insert at the beginning of the song to direct the motif rack to restore the output back to Assigned Output L or R.

It is in the Data List Booklet on page 74

F0 43 10 7F 03 37 pp 1F dd F7

F0 = Start of Exclusive
43 = Yamaha Manufacturer ID
10 = Parameter Change/first device
7F 03 = Motif XS-series product ID
37 pp 1F = The High/Mid/Low address of the OUTPUT SELECT parameter for a PART, where “pp” is the PART number 00-0F (Parts 1~16)
dd = Data Byte, where

00 = main L/R
08 = asL/R
40 (64) = asL
41 (65) = asR

F0 43 10 7F 03 37 03 1F 41 F7

this would send PART 4 of a MULIT to the asR Output… Make sense?

F0 41 10 42 12 40 1A 15 02 0F F7

This does not address a Yamaha product, but I bet it reassigns the outputs on a Roland product

F0 is Start of Exclusive
41 is Roland Manufacturer ID
The rest is unknown to me… sorry I don’t speak “Roland” sysex… :^)

Ah - we had a Roland way back when we started, years ago.  So, I’m guessing 2 lines of sysX, one for asR and 1 for another channel to asL, will do it.  Thank you!