How to adjust valves on briggs and stratton 17.5 h.p. troy bilt lawn tractor

Remove spark plug
Remove cover from engine that covers the flywheel
Remove rockerarm cover or valve cover
Find TDC (top dead center) by rotating the flywheel by hand and your finger over the spark plug hole as you rotate the flywheel you will feel pressure against you finger at some point then stop.
This is the compression stroke it is called now find a long slim round piece of plastic or plastic ink pen to stick in the spark plug hole (If you are careful a slim screwdriver can be used ) and find the piston top, then slowly rotate flywheel again (cw) as the piston is moving up pushing the plastic up as you rotate the flywheel slowly.
a max. piston up or tdc as you turn you will feel and then the piston starts to go the other way,at that transition this is tdc (piston is on top of stroke) leave it there,,both valves should be closed at that point.
Have a feeler gauge and set the exhaust valve at a loose .002 and the intake a loose .004 be sure engine is cold when valves are adjusted
Feeler gauge goes in between the rocker arm tip and valve stem top for each valve setting.
Note the rocker adjustment at the push rod side of each valve by tightening and loosening to make adjustments,lock your adjustments in place and rotate flywheel a few times and recheck settings