1980 Johnson 2HP Service Manual, Page 15Get this manual
TUNE-UP PROCEDURE
When an owner brings motor to for tune-up, or for some minor operating malfunction, the following procedure should used as guide to determine the cause of the malfunctionWrite down the owner' commentsan accurate card file your service shop operationEach service operation should record as to the: OWNER'S NAME DATE MODEL NOSERIAL NONATURE OF COMPLAINT NATURE OF WORK PERFORMED COST OWNER WAS WORK PERFOMED UNDER WARRANTY? After writing down the owner's comments, check the motor visual1y and begin systematic tune-up procedureConsult the Trouble Check Chart to find the causes of any malfunction which discovered when tuning the motor1Remove exhaust cover and cylinder headSlowly rotate flywheel and visually inspect piston, rings, and cylinder for wear, freeness, and carbon deposits
Piston ring condition should determined before continuing tune-upGum and varnish deposits rings or piston removed with application of Engine CleanerIf piston, cylinder, and rings are considered to
in satisfactory condition for continued service, clean carbon, reinstall cover, using new gasketClean carbon from cylinder head and top of pistonDo not alter piston deflectorSurface and reinstal1 cylinder head, using new gasket