CD, yeah I have noticed using a digital ball mic that the manufactures have started doing different things with sleeve taper to hopefully achieve longer engine life in the "sweet spot". The original ds had a visible step 2mm under the bottom of the port openings. As far as what I saw with the Ninja I gave it a couple of more tanks on the bench. Track running I did a tank at 240,250 and 260. Still plenty of smoke down the long straight so we start turning the needle..."when in doubt, lean it out".