2007 Johnson 2 HP 4-Stroke Service Manual, Page 84Get this manual
POWERHEAD CYLINDER HEAD Measure the valve seat contact widthIf the measurement exceeds the service limit, replace the valve spring
Valve Spring Preload
Measure the valve spring preload
1Valve seat contact area
Valve seat contact width: INEX: 0.03 to 0.04 in(0.8 to 1.0 mm) If measurement exceeds specification, repair valve seatClean and assemble the cylinder head and valve components006048
IMPORTANT: Fill the intake and the exhaust
ports with solvent in order to check for leaks between the valve seat and the valveIf any leaks occur, inspect the valve seat and the face for burrs or debris which could prevent the valve from sealing
Valve spring preload: Standard INEX: 8.05 to 9.24 lbs(3.65 to 4.19 kg) for 0.6 in(15 mm) Service limit INEX: 7.34 lbs(3.3 kg) for 0.6 in(15 mm) If the measurement exceeds the service limit, replace the valve spring