I think the oil in the Honda is getting frightened by the loud mufflers and causing it to decompose from the mental stress! 
..............
I don't know if its "High-Speed" or not but I'm not shy about running the high side of 70 on the speedometer. There is a error of about (10 % +) , so an indicated 70 is really near 80 mph on the GPS. I'd guess about 5k RPM is the most mine ever see's .
but
I never have to add oil.
T-6 plus about 1/2 can of reg. STP. to the upper full mark on the side stand. No , the clutch don't slip.
It only had about 3k miles on it when I bought it , and it was still idled at 1200 rpm-ish . I don't think its ever been mis-treated or idled down too low. Now its up to the 50,000 mile neighborhood and doing fine.