2003 ST 4 Stroke 9.9/15HP Johnson outboards Service Manual, Page 127Get this manual
POWER UNIT INSPECTIONSERVICI NG
Valve seat cutter (NEWAY 122) Valve seat cutter (NEWAY 121) Handle adapter (N-503-1) Solid pilot (N-100-5,52) Handle (N-505)
Contact area too high and too wide on face of valve
1Insert solid pilot and the 45 valve seat cutter2Turn the cutter clockwise, never counterclockwise3Inspect the valve seat widthSee Valve Seat Width on page 6-20 4If the contact width is too high (or wide) on the valve, use the 15 valve seat cutterIf the contact width is too low (or narrow) on the valve, use the 45 valve seat cutter5After desired seat position and width is achieved, use the 45 cutter very lightly to clean up any burrs