Back in the 80's there was a regular feature in Creem magazine called "Stars Cars," and one has Sting pictured sitting on a Yamaha, but it has no real info on the bike.
This is what the caption says:(it's pretty strange)

Sting
Hey! Who's that cool lookin' blonde dude on the bike?
Say "De Do Do Do De Da Da Da" to the famous Sting,
bassist extraordinaire, matinee idol and lead
squealer of the world's most phenomenally popular
trio of platinum tops. Sting may be only a spirit in the
material world, but when it comes to materials in the
material world, one of his favorite material things is
his Yamaha hog! "I don't want a pickle! I just wanna
ride my motorcycle!" exclaims Sting, taking a cue
from his big idol, Arlo Guthrie. And with that, he's
off to work on the Police's next LP, Outlandos
d'Motorcycles!

Tracey