My 85 ninja 600 sputters around 6000 - 6500 RPM @ 140km / h (6th gear). THe only way I can get around it is to drop to 4th gear (RPM's to 9000) then keep the rev's high through 5th and 6th but the bike sheds speed a little quicker than I like.
By sputters - I mean it hestitate and sorta rattles - the same sensation when you feel leave a stop sign in the wrong gear. (underpowered). You can hear the motor (different tempo), and feel the accelleration slip in an out of a "power band". Its wants to go, but maybe starved for fuel for small instances.
The specs indicate a top speed of 202 km/h (127mph), but I'm guessing thats a fresh engine, nice long stretch - an maybe a tailwind. The max BHP was 76 @ 10500 - 11000 RPM (so maybe 68 at the final drive).
So, do I invest in a carb tuning / jetting, etc, or do I just settle into the fact that its just an older bike with 592cc's with not a lot of ft/lbs of torque doing what it can with my fat a$$ on it? I've already seafoam'd, gas treated, running supreme - or pretty much anything else thats a low $$ fix.