Yamaha F100B F100C Outboards Factory Service Manual, Page 121Get this manual
Cylinder head Replacing the valve guides
1Remove the valve guide by striking the special service tool from the combustion chamber side
Valve guide removerinstaller: 90890-04064 2Install the new valve guide by striking the special tool from the camshaft side to the specified position a
NOTE: Turn the valve guide reamer clockwise to ream the valve guide Do not turn the reamer counterclockwise when removing the reamer
Valve guide reamer: 90890-04066 4Measure the valve guide inside diameterReplace the valve guide if out of specificationValve guide inside diameter: 6.016.02 mm (0.23670.2370 in)