I'd not be comfortable with just a zip tie. Why not take the belt off the airpump until you get what you need.
There is no belt on the air pump. Since I didn't order the rubber mounting bolts with the new pump (and didn't know about them), when I removed the old pump, two of the bolts fell apart and I can't put the old pump back in place. I figured that it would be easier to cover the hole on the airbox instead of covering the open-end of the hose coming off of it.I'd not be comfortable with just a zip tie. Why not take the belt off the airpump until you get what you need.