1990 Johnson Evinrude "ES" 40 thru 55, P/N 507872, Page 94Get this manual
1221 6 equalization hose between carburetors and secure With tie strap
7Connect drain hose to air silencer base8Install new air silencer base to carburetor gasket and secure air silencer using new screws9Install air silencer cover using new gasket10Install air silencer screws and secure the air silencer coverIf the slow speed needle adjustment has been disturbed, refer to Carburetor Mixture Adjustment40, 48, 50
Carburetor Mixture Adjustment40, 48, 50
The slow speed mixture in this carburetor is controlled by factory adjusted needleThis procedure should only be used if the factory seal is gone or if the needle adjustment has been disturbed
1231 1Make reference mark on the adapter sleeve before you
disturb the needle adjustment2The boat must be in the water, under normal operating conditions with the correct propeller installedThe boat's movement must be unrestrainedThe boat must not be tied to dock or trailer3Start the engine and allow it to reach normal operating temperatureRun the engine in gear at slow speed (700-800 RPM) for three minutes If the adjustment is too lean, the engine will sneeze and backfire, go to Step Ifthe adjustment is too rich, the engine will be rough and unsteady, go to Step 54If the adjustment is too lean, notice your reference mark and turn the needle V12 revolution counterclockwiseWaiting 15 seconds after each adjustment, repeat this procedure until you reach the highest consistent RPMU