Driving vibration RXV at speed

[Vulcaneer]

A serious vibration. Very much like out of balance wheels. It is rhythmic, and rotational. Not under acceleration or deceleration. But while feathering the throttle at 1/2 to 3/4 speed. When it does this there is also a clattering sound, coming from the area of the motor. Don’t know if that is related. Cart is in Freedom mode at 19.5 MPH Max.

This cart is a 2019. While it was claimed to be new by one sales person, another reported it as used. Although in like new condition. Sales receipt declares it as used, with used warranty. Couple of thousand below new price. I’m thinking a demonstrator or repo. Based on the dirt and sludge under the body work and hubcaps. I do have a 1 year warranty. But if it is something simple, I would prefer to repair myself.

Any ideas?