I did it a bit different. The zip tie is just too thin and doesn't make enough of a difference IMHO.
I started with a $2- piece of pVC from Ace hardware, I had 2 part plastic epoxy already but it's about $6- if you need to buy it.
Next I cut the PVC to the same width as the tube
I then clipped it so that it would wrap correctly
Finally I epoxied it to the throttle tube and used my dremel to just bevel the edges a bit.
That was nice, but after a few track days I realized I wanted the throw even shorter so I cut another piece and doubled it up. That resulted in some dragging inside the throttle tube so I dremeled it down a bit until it spun freely and NOW it is perfect.