Suzuki 2003-2007 DF60 DF70 Outboard Motors Service Manual, Page 160Get this manual
POWER UNIT
5Refinish the valve guide bore09916-34520: Valve guide reamermm) 09916-34542: Valve guide reamer handle NOTE: Clean and oil the valve guide bore when reamed
VALVE SEAT SERVICING If the valve seating contact width is out of the specification, reface the valve seat as follows: 09916-24940: Solid pilot (N-150-7) 09916-54910: Handle (N-505) 09916-24935: Valve seat cutter (N-608) 09916-24910: Valve seat cutter (N-212) NOTE: Turn the cutter clockwise, never counterclockwise1Insert the 45 cutter and reface the valve seat2Measure the valve seating contact width ASee the "Valve seating contact width" section on the page 6-233If the width is too high (or wide), reface the valve seat using the 15 cutterIf the width is too low (or narrow), reface the valve seat using the 45 cutter4Clean up any burrs using the 45 cutter very lightlyGrind the seat areas minimally onlyDo not grind more than necessary5Recheck the valve seat contact width ADo not use lapping compound after the final cut is madeThe finished valve seat should have velvety smooth finish and not highly polished or shiny finishThis will provide soft surface for the final seating of the valve which will occur during the first few seconds of engine operation