I am just setting up a new-to-me rotax and I don’t have anything to go in between the metal elbow and the throttle cable. However, the throttle cable has a metal tip on it already so it will be metal to metal.
I don’t remember having anything on my old one other than a little rubber boot to cover the connection, however when looking at the diagram there are four parts labeled as a “Throttle Cable Fixation kit.” What is the purpose of these, and are they needed?
Are they absolutely needed, no. Parts 9 & 10 are a means to adjust the throttle cable. You might have an adjustment screw similar to part 10 at the chassis tab where the sheath for the throttle cable ends with a nut to prevent it from turning. The concern would be the tube that is attached to the carb top is threaded on the inside to accept this adjuster and might wear the throttle cable if not in place.