Thanks for the reply puppypligrim, That is the same as mine.
However, it does the same thing when the bike is freewheeling with the motor off the ground.
I kind of expected some noise when it is under load, but it will do it without a load, and the noise will
vibrate through the frame to the point where it makes my hands numb.
But, like yours if I pedal more, or reduce the throttle, it goes away. At full speed, it is gone too