1973 Evinrude Norseman 40 HP Service Manual, Page 11Get this manual
TUNE-UP PROCEDURE Wheh an owner brings motor to you for tune-up, or for some minor operating malfunction, the following proced're should be used as guide to determine the cause of the malfunctionWrite down the owner',s commentsKeep an accurate card file on your service shop operationEach service operation should be on record as to the: OWNER'S NAME DATE MODEL NOSERIAL NONATURE OF COMPLAINT NATURE OF WORK PERFORMED COST TO THE OWNER WAS WORK PERFORMED UNDER WARRANTY After writing down the owner's comments, check the motor visually and begin systematic tune-up procedureConsult the Trouble Check Chart to find the causes of any malfunction which may be discovered when tuning up the motorSAFETY WARNING KEY SWITCH MUST BE IN OFF POSITION BEFORE ATTEMPTING ANY REPAIRS ON ENGINE EXCEPT WHERE OTHERWISE SPECIFIED1Remove exhaust cover, intake by-pass covers, and cylinder headsSlowly rotate flywheel and visually inspect pistons, rings, and cylinders for wear, freeness, and carbon depOSitsClean carbon from cylinder head and top of piStonsDo not alter piston deflectorSurface cylinder head and reinstall, using new gasket; Tighten cylinder head screws to specified torqueInspect spark plugsplace as necessaryClean and re-gap or re-