Does the Scooter Cannonball allow modified scooters?
If so, put 15% taller rear gears in, put 8.5 grams of 0.6 micron tungsten disulfide in the engine oil and 1.75 grams in the gear oil, pump up your tires to 40 psi, put in 1000 RPM clutch springs, and drop in a Pulstar HE1HT9 spark plug. It'll hit 85 MPH and *still* get ~75 MPG. If you take it easier on the throttle, you'll be getting in the 90 MPG range. Drop 200 ml of acetone and 200 ml of water in with your fuel, and it'll have more than enough power for anything you want to do (only do that with E10 gasoline... with straight gas with no ethanol, you have to use less water).
If you want to get fancy, drop in ceramic or hybrid-ceramic bearings in your wheels and rear gears to lower friction... the thing will roll so easily it's not even funny. You can still cut bearing friction a good bit just by mixing in tungsten disulfide with your grease, though.
Even with the taller gearing, it'll still have plenty of oomph to pull up steep hills. Mine will do 68 MPH up the interstate hills around here, and can climb the steep hills in the Oakland Hills at only 5000 RPM without breaking a sweat.
I did all the above to my Yager. It cruises at 65 MPH at 6750 RPM. If I used the OEM belt (which is ~1 mm wider) instead of the Gates Boost+ Kevlar belt, I'd be hitting 65 MPH at 6500 RPM. Red-line on this bike is 8000 RPM, and the rev limiter is at 9200 RPM... so a hard break-in of the engine to get good ring seal means you'll have plenty of headroom for a higher top speed.