Alright, I spent 2.5 hours with her, and here's the verdict,.. it's sort of fixed,.. and I'm not sure why.
I did all of the following:
Re-routed the throttle cable to be under the brake line ( not over like the service manual wants)
Re-routed the Main harness to be over the air box, previously it was under it, and possibly causing crowding issues?
Re-seated the carbs on the engine
Tied the main harness to be away from the throttle cable, so it couldn't interfere at all.
Cursed at her, told her she was going up for sale ( I think that was during the "airbox re-installation" phase.)
Checked the grip
The grip -looked- ok, nothing looked out of place, or burred, worn should in theory give me more play, but nothing even looked worn in the grip.
In fact, the only thing that looks worn is the little "pin" on the carbs that the throttle seems to snap against when you let go of the throttle. ( the one that moves up and down when you adjust the idle speed)
In the end, I have her "down" to a slow climb to about 2400rpm ( from about 1500 rpm) when you turn the bars all the way hard right.
There's still absolutely no slack, but I don't think she's going to blow her engine on startup anymore.
Anyone else have any more ideas?