Kohler 114749-9-AE Service Kit Instructions page 8

Hook
Chain
Flapper
Flush Valve Seal
6. Attach the Flapper
Attach the flapper to the flush valve.
Remove the hook from the chain, and reinstall it at the same
chain length as the original flapper.
Attach the hook to the trip arm.
Check for correct operation. There should be some slack in the
chain when the flapper is at rest.
If necessary, adjust the hook as needed to achieve correct
operation.
Using a pliers or wire cutter, remove all but three of the extra
chain links.
114749-9-AE 8 Kohler Co.