Just an FYI, but I put a 2017 OEM slipper clutch in my 2007 Ninja 650. It has worked fine in the limited time I have used it (3 trackdays, 2 race weekends). It was less than half the price of a Yoyodyne which allowed me to buy a second one for my other 2007 Ninja 650. I took a gamble on the engine internals still being similar after ten years and luckily the clutch system appears to be interchangeable. I have never had a slipper clutch in my bikes previously, so do not have a comparison to a Yoyodyne or other aftermarket slipper. It works well for taming the rear end coming into the corner. If I am high speed and slam the clutch out, I can still get a little bit of wheel hop, but nothing like when I was on the standard clutch. Watch Ebay for used 2017+ OEM clutches for Ninja 650, Z650.