1998 Johnson Evinrude EC 5 thru 15 HP Four Stroke Service Manual, Page 79Get this manual
Carburetor Mixture AdjustmentAll Models
Important EPA emission regulation prohibits tampering with emission related adjustmentAfter repair or replacement, the idle mixture adjustment procedure must be followed After final adjustment, the adjusting screw head must be concealed by filling cavity in cover with RTV silicone rubber adhesive sealant1Start the engine and run it in FORWARD at one-half throttleAllow the engine to reach normal operating temperature
2Tiller ModelsFacing steering handle, turn idle speed adjustment knob counterclockwise to full SLOW speed position3Use OMC Idle Adjustment Tool, PI 910245, to adjust idle mixture4Run the engine at slow speed and adjust the idle mixture needle until the highest consistent RPM is attainedAllow 15 seconds after each adjustment for the engine to respond
5After the final adjustment is completed, turn the idle mixture needle counterclockwise one-eighth turn to prevent lean condition, particularly in NEUTRAL6Reduce engine speed and turn the idle speed adjustment to allow the engine to run at minimum of 800 RPM on .915 (305cc) and 850 RPM on thru 9.9 (211cc) models in FORWARD7Run the engine in gear near full throttle for one minuteQuickly reduce speed to SLOW and shift into NEUTRALThe engine should continue to run smoothly8If the engine stalls or pops, the mixture is too leanTurn the needle counterclockwise 116 turnAllow 15 seconds after each adjustment for the engine to respondRepeat Step to verify that the mixture adjustment is correct9If the engine does not respond to adjustments, check it for other problemsMake sure gasoline is of good qualityAfter final adjustment is made, verify idle speed adjustment as described in Synchronization and Linkage Adjustment, Section 1"'"-'-=:::::-'