1970 Johnson 1.5 HP Outboard Motor Service Manual, Page 13Get 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 OWNER WORK PERFOMED UNDER WARRANTY? After writing down the owner' comments, check the motor visually 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 flywhe and visually inspect piston, rings, and cylinder for wear, freeness, and carbon depositsSPECIAL NOTE Piston ring condition should determined before continuing tune-upGum and varnish deposits rings piston removed with an application of Accessory Engine CleanerIf piston, cylinder, and rings
considered to in satisfactory condition for continued service, clean carbon, reinstall cover, using new gasketClean from cylinder head and top of pistonDo not piston deflectorSurface and reinstall cylinder using new gasketInspect spark plugClean and regap or replace as necessary