August, 1975, Yamaha RD-250 (little brother to the orange tank giant killer RD-350) Houston, Tx to St. Louis; Houston to Little Rock, then I-40 to Memphis, and up I-55 north to St. Louis. About 900 miles, 20 hours straight. Do not try this, EVER. I remember my last gas stop, but I don't remember the miles between that and my second-last stop. 70 mph, 2 AM, on autopilot. Scary. No windshield or any mods other than a luggage rack, S&W shocks/springs, and slightly lower bars.
Don't remember any major consequences, other than sleep loss.