Vex motor code help need

If you have the two-wire-version it will work definitely not with the servo-library.
This motor looks like a servo but the two wire-version is not a servo
This company is bad on documentation. at first glance the website looks like explaining all things but it doesn't.

The two wire-version must be driven not with the servo-library but with function analogWrite()

About codetags: make the code look like this

this is text 
formatted with code-tags

use the </>-Button

best regards Stefan