1978 Evinrude Outboards 9.9/15HP Service Manual, Page 14Get this manual
TUNE-UP PROCEDURE When an owner brings motor to you for tune-up, or for some minor operating malfunction, the following procedure 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 MODEL NOSERlAL 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 motorELECTRlC START MODELSDISCONNECT BATTERY CABLES AND COVER RED POSITIVE LEAD WITH INSULATING BOOT, BEFORE MANUALLY CRANKING ENGINE OR ATTEMPTING ANY REPAIRS ON ENGINE EXCEPT WHERE OTHERWISE SPECIFIEDSPARKS COULD IGNITE GASOLINE FUMES1
If pistons and rings are considered to be in satisfactory condition for continued service, remove carbon, surface and reinstall covers, using new gaskets34