"Class D" license? Whats that?
Here in MI we just have Operator (meaning, you can drive), Chauffer (meaning, you can drive up to like 15 others), and CDLs. You can get cycle endorsements, etc, added to 'em. Our cycle endorsement is a "one size fits all". Did mine on a 125cc zuki enduro, and ride a 900rr around now. Some states apparently make you qualify for certain sizes of engines...?