If you have a digital caliper check the distance on those bolts, should be 90mm apart (to the center of each bolt) for the JT269 sprocket. I just put a JT269 sprocket on my 'Bashan WILL' and all I did was measure with a $12 digital caliper
I personally went with a 39t sprocket, for a few reasons, main one being...
I got it from Amazon Prime shipped it for under $16
and I was on a 'budget' for 'upgrade parts' at the time
Top speed should now be over 80mph... if the little 197cc engine has enough torque to pull that gearing I don't know just yet... still waiting on carburetor jets and finish my exhaust install.
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