1990 Johnson Evinrude "ES" 40 thru 55, P/N 507872, Page 95Get this manual
12415If the adjustment is too rich, notice your reference mark 15 revolution clockwiseWaiting and turn the needle 112
seconds after each adjustment, repeat this procedure u"til you reach the highest consistent RPM6Repeat Steps thru for each carburetor7To test your adjustment, run engine near full throttle for three minutesReturn the engine to idle in gearThe engine should maintain smooth idle RPM If your test results vary, repeat Steps thru 58Use RTV Sealer, OMC PIN 263753, to seal the end of the adapter sleeveIf the engine does not respond properly to these adjustments, check the following: Engine temperature Linkage adjustments External recirculation system Sufficient exhaust back pressure Pulse equalization hose