1997 Johnson Evinrude "EU" 9.9 thru 30 2-Cylinder Service Manual, P/N 507263, Page 81Get this manual
Carburetor Mixture Adjustment9.915 1Start the engine and run it in FORWARD at one-half throttleAllow the engine to reach normal operating temperature
2Tiller ModelsAs you face the steering handle, turn the idle speed adjustment knob counterclockwise to full SLOW speed position
3Run the engine at slow speed (700-800 RPM) and adjust the low-speed needle until the highest consistent RPM is attainedAllow 15 seconds after each adjustment for the engine to respond4After the final adjustment is completed, turn the low-speed needle counterclockwise one-eighth turn to prevent lean condition, particularly in NEUTRAL5Reduce engine speed and turn the idle speed adjustment to allow the engine to run at minimum of 650 RPM in FORWARD6Run the engine in gear near full throttle for one minuteQuickly reduce speed to SLOW (700-800 RPM) and shift into NEUTRALThe engine should continue to run smoothly7If the engine stalls or pops, the mixture is too leanTurn the needle counterclockwise lA6 turnAllow 15 seconds after each adjustment for the engine to respondRepeat Step to verify that the mixture adjustment is correct8If the engine does not respond to adjustments, check it for other problemsMake sure gasoline is of good quality and mixed with the proper amount of oil