Knock after shutting throttle

[mcman56]

I recently had to replace the stator on my Rev3 200. On the first ride out there was some very serious knocking...at this point I don't remember if it was off throttle or if it was also bogging on throttle. Raising the needle two steps to full rich resolved the severe problem. (This is also about the time it got hot and very dry in northern CA so would include a change to summer gas.) Now I get some fairly minor repeat knocking and a little rolling of engine speed when cutting the throttle. Cutting throttle, it feels a little lean but applying throttle there is no bog or knock. It runs OK but not great. I had a Sherco 2.9 that would knock just once sometimes when chopping the throttle but this feels different. I believe the previous owner ran race gas. I have gone up two sizes on the pilot jet and retarded timing 2mm back to the stock setting with little effect. I had also fooled with the carb when diagnosing the stator issue. Various float level settings seem to have little effect. The idle mixture screw seems to have less effect than I expect but I have no experience with Betas breathing through Mikunis.

So...could this just be an expected result of heat and summer gas? Could it be something else? What are the symptoms of a bad crank seal on the stator side?

[chewy]

The stators are not neccesarily all the same...I would have thought ..changed staotor.. starts pinking/knocking.....spark timing different????