1968 Evinrude Big Twin, Big Twin Electric, Lark 40 HP Outboards Service Manual, Page 14Get this manual
TUNE-UP PROCEDURE When an owner brings motor to for tune-up, for minor operating malfunction, the following procedure should used guide to determine the of the malfunctionWrlte down the owner' commentsan accurate card file service shop operationEach service operation should record to the: OWNER'S DATE MODEL NOSERIAL NONATURE OF COMPLAINT NATURE OF WORK PERFORMED COST OWNER WAS WORK PERFORMED UNDER WARRANTY? After writing down the owner's comments, check the motor visually and begin systematic tune-up cedureConsult the Check Chart to find the of any malfunction which discovered when tuning the motor1Remove exhaust covers, cylinder heads, and intake coversSlowly rotate flywheel and visually inspect pistons, rings, and cylinders for wear, freeness, and carbon depositsSPECIAL NOTE Piston ring condition should determined before continuing tune-upGum and varnish deposits rings pistons removed with an application of Engine CleanerIf pistons and rings
2Clean carbon from cylinder head and top of pistonsReplace bearing crankshaft sealSurface and reinstall cylinder head, using new gasket3Inspect spark plugsClean and regap replace necessaryInstall new bearing seal4Inspect and test points, condenser, coil, and ignition wiresSee Section for test proceduresCheck for spark each cylinder 5Inspect carburetor and automatic choke6Inspect fuel ment and gasketand linesReplace filter ele-