1977 Evinrude 4HP Outboards Service Manual, PN 5303, Page 12Get 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 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 motor1Remove exhaust cover and cylinder headSlowly rotate flywheel and visually inspect pistons, rings, and cylinders for wear, freeness, and carbon deposits 234567891011
If pistons, cylinders, and rings are considered to be in satisfactory condition for continued service, reinstall cover, using new gasket