Output Shaft rotational play?

Replaced the front sprocket this weekend and noticed that the output shaft (that the sprocket mounts on) can freely rotate about 20 degrees before coming to a dead stop. That 20 degrees is about 1 full notch (tooth to tooth) of the sprocket.  Bike is an 80 kz650.  I couldn't find a spec on that, on any bike for that matter, in my Chilton book.  ?Is that much play normal?  Its the same in all 5 gears.  I'm kind of new to motorcycles.  

Some lash is normal. The Primary drive chain, clutch basket, primary gear, transmission gears, all have acceptable tolerances for backlash and can be found in the factory service manual - which is better than Chilton in every way. These small tolerances in lash have a stack effect that is seen at the output shaft. Maybe another member can chime in to what they have, that doesn't seem that far off normal for most bikes. Unfortunately measuring most of those things requires splitting the cases, I would run it and not worry about it.