ANSWER: The VH-SPORT RO model will be the best carrier for your Burgman scooter. This has a 600 lbs carrying capacity and has a 77.5″ long rail. Dimensions are listed on http://versahaul.com/vhsportro.php
Please visit the above link for vehicle and hitch limitations.
Check that your hitch is not recessed behind your motorhome’s bumper or that a ladder or spare tire is in the way. The VH-SPORT can be customized to have a longer 30” main tube to avoid obstacles. Usually this is not necessary. http://versahaul.com/vhCustom.php
The exhaust from a Diesel Pusher may require the purchase of a longer main tube because the hot exhaust may damage the paint of the tie-down tube.