1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 177Get this manual
POWER UNIT 6-34 VALVE SEAT SERVICING If valve seat contact width is out of specification, reface valve seat as follows : Valve seat angle Intake side30, 45 Exhaust side15, 45 09916-20620 09916-20610 09916-20630 09916-24440 09916-24450 09916-54910Valve seat cutter (NEWAY122) 45Valve seat cutter (NEWAY121) 15Valve seat cutter (NEWAY 126) 30Handle adaptor (N-503-1)Solid pilot (N-100-5.52)Handle (N-505)