Small Engines (Lawn Mowers, etc.): valve adjustment, valve adjustment, plug hole

Question
engine # 12s502 0114 b1 070319FA
John Deere GXJS40A 190cc ohv Briggs motor
need to know how to adjust valves

Answer
On youtube there are several videos on valve adjustment which are helpful, and will outline it quite easily.

You will have to remove the valve cover, get a set of feeler gauges.
Remove the plug, set the piston at top center, with a pencil in the plug hole so you know when the piston is all the way up, it goes to top twice, one time, one of the valves is closing while the other one starts to open, you need to go to the other time, when both
rocker arms are still.
Then rotate just a hair past that, when the pencil just starts to move back down, and adjust them at .004-.006.