This looks like the ideal application for a quick-link. The hobby shop sells them. It's a cube of brass with a hole for your pushrod and a pin sticking out opposite the setscrew. Comes with a steel pushnut that holds the pin through your throttle arm.

Use pushrod material, not music wire. The pushrod wire is soft, and the setscrew will bite in - the music wire is hard, the screw won't make a dent in it, and will work loose. In fact, some people use thread locking compound on the setscrew. I've never used threadlock, just Dubro pushrods.

Good luck,
Dave Olson