I had a hell of a time setting up the throttle arms. This was part of my tantrum in the previous post!
But basically you can avoid a lot of time and stress by being really careful fitting the armrest plates. I didn't make them conform closely enough to the curve and they sat a millimetre or two off the armrest. The problem there is that the throttle arms have a bend in them and there isn't much leeway for error. Where the arm bends, it rubs on the plate, causing way too much friction. I ended up drilling out the rivets (TWICE on the left hand arm!) . I filled the holes up with epoxy putty and redrilled. I took care to push the plates as hard as I could. But what I also did is redrilled with a smaller drill bit. Through the hole in the plate but as low as I could. Therefore when I drill that hole the correct size, the hole is maybe a millimetre lower. That helped pull the plate just a smidge lower again.
Pic shows how far the plate was off when I first attached it.