1969 Evinrude 40 HP Big Twin, Big Twin Electric Lark Service Manual 4596, 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 theOWNER'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 pro cedureConsult the Trouble Check Chart to find the causes of any malfunction which may be discovered when tuning up the motor1Remove exhaust covers, cylinder heads, nd intake by-pass coversSlowly rotate flywh ee and visually inspect pistonsrings, and cylinders for wear, freeness, and carbon depositsSPECIAL NOTE Piston ring condition should be determined before continuing tune-upGum and varnish deposits on rings or pistons may be removed with an application of OMC Accessory Engine CleanerIf pistons and rings are considered to be in sat-