I hope you get it straightened out. Perhaps one of the wheels is not actually turning--not actually driving--just going along for the ride. Smart Steer may be the heart of the problem, good comment DA.
Jack it up and watch how the wheels spin. See what happens when you turn the handlebar. Make sure the brakes are not dragging. Check to see if the rear wheels turn easily--add grease to back wheel bearings. Also front. WD 40 or grease or lube everything that you can. Check oil level in transmission.