1975 Evinrude 2HP Model 2502 Full Factory Service Manual, Page 15Get this manual
2-8 TUNE-UP PROCEDURE
When an owner brings motor to you for tWle-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 PERFOMED UNDER WARRANTY?
After writing down the owner's comments, check the mowr visually and begin systematic tune-up procedureConsult the Trouble Check Chart to find the causes of any maliWlction which may be discovered when tuning up the motor1
Remove exhaust cover and cylinder headSlowly rotate flywheel
and visually inspect piston, rings, and cylinder for wear free ness, and carbon deposits
Piston ring condition should be determined before continuing twte-upGum and varnish depOsits on rings or piston may be removed with an application of OMC Accessory Engine CleanerIf piston, cylinder, and rings are considered to be in satisfactory