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.
LAD Specialties customer / tony kart / rotax / kt100