You beat me to it Michael. It was called the GPz 305 over here, and it was quite a good little bike in it's day.The Kawasaki KZ305 of the early to mid '80s was available with belt drive. The BMW F650 was also available with belt drive. Other than that, in recent times belt Harley is about the only manufacturer to adopt belt drive on any scale.
The idea is attractive. Belts are quiet and smooth. They are nearly maintenance free with a long life, but do have to be replaced on schedule. They looked a good option compared to the standard chain.
However since o-ring chains arrived on the scene the most of the disadvantages of the chain have been overcome. An o-ring chain life is as good as a belt with minimal maintenance compared to a standard chain.
1986 Kawasaki GPZ 305 Belt Drive specifications and pictures