I've had 2 Kawasaki triples in my youth (teens), and, I wish I had both of them today. As a consolation, I do own a '76 Honda CB 550 K that is 95% original with only 11,xxx miles on it. Anyway, the first was a a 3 year old ('73) Kawa. 250, 13,000 miles. I thought it ran fine but I wouldn't beat a Honda CB350 twin. I was 17 & it was gone in a year or so. The second was a later model '76 500 with 7k mile or so but it (in hindsight) wasn't tuned properly & wouldn't beat the newer Kawasaki 650 four cylinder. I was young & didn't know how to treat engines. One realizes that 2 strokes will go the distance equal to their 4 stroke brothers. After all, what changes?, nothing really. Still a piston in a cylinder, only with a little different valving & oiling. Keep the piston speed down to sensible levels, same with overall temperature, & there ya go.