I had the 1970 model of that bike (the black one). It was a rocket with no brakes. It was the worst death trap I have ever owned.
Yeah, but I'll bet you had one hell of a grin on your face while you were accelerating, before it turned to a grimace of fear, and you started screaming like a little girl, when you wanted to slow down and turn!
Don't feel bad, everyone did that on that bike! But look at it this way... At least you have an idea of how Kenny Roberts felt when Yamaha shoehorned a TZ750 motor into their dirt track bike for him.
Kawasaki has a long history of shoehorning the biggest, most powerful motor into a frame that really has no business in a bike like that... They did it with the Z1 (900cc motor in a frame perfect for a 650, and the KZ-550, which had a frame designed for a 350cc bike). Both bikes, by the way, were a real blast to ride. So were the H2 and H3 bikes (as long as you didn't really want to turn or stop).
Mark