Those crowfoots can sure be a saver at times. I seldom utilize mine, but when you need one, more often than not nothing else is going to the job or you're taking a lot of things a part to get the access.
Yep, I just had to fix my throttle lever last night too. The washer looked ok (it is the fibre one and didn't look broken from what I could tell) but the lever would slowly move down to a lower RPM as I was working. I have 65 hours on the machine. Had to remove both side panels, insturment cluster panel, steering wheel, parking brake and cruise control levers just to get access to the 2 nuts on the left side of the throttle assembly and tighten them. Seems tighter for sure, but I should get chance to use it today and I'll know for sure. Definite PIA to get to and fix.
I can't tell for sure in the picture but do you have just 1 nut or 2? (haha, ya, ya I know) I believe you need 2, the first one tightens and the second one locks the first one (at least thats what mine does I assume)