1. Remove the spark plug wire and spark plug.
2. Remove the valve covers.
3. Turn the engine crankshaft until the piston in the cylinder you are adjusting is at top dead center (TDC). This can be done by inserting a thin rod or screwdriver into the spark plug hole and turning the crankshaft until the rod stops moving up or down.
4. Measure the clearance between the valve stem and the rocker arm. The clearance should be 0.004 inches (0.1 mm) for both the intake and exhaust valves.
5. If the clearance is too small, loosen the locknut on the rocker arm and turn the adjusting screw counterclockwise until the correct clearance is achieved.
6. If the clearance is too large, loosen the locknut on the rocker arm and turn the adjusting screw clockwise until the correct clearance is achieved.
7. Tighten the locknut on the rocker arm.
8. Repeat steps 4-7 for the other cylinder.
9. Replace the valve covers.
10. Replace the spark plug and spark plug wire.
By following these steps, you can properly adjust the valves on a 17.5 Briggs and Stratton engine C-707.
