I circled the area I want you to check. It looks like your engine has those valve buttons/caps on the end of them. Look and make sure you haven't lost one.
View attachment 54703
Hi Fish, this is RLM20001 I checked the movement of the valves, the top valve is moving 11.49 mm (.453 in) the bottom valve is moving 11.37 mm or (.447 in) the piston moves approximately 88.61 mm or (3.89 in)Briggs and Stratton Valve Clearances
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