1990 Johnson Evinrude "ES" Colt/Junior thru 8 Service Manual, P/N 507870, Page 47Get this manual
4Run engine at slow speed (700-800 RPM) and adjust the lowspeed needle until the highest consistent RPM is attainedAllow 15 seconds for the engine to respond to adjustment5After final adjustment is completed, turn low-speed needle counterclockwise one-eighth turn to prevent engine from being too lean at slow speeds Adjustment of high-speed needle must be repeated after final low-speed needle adjustment oRepeat
high speed adjustmentAfter final adjustment is completed, turn high -speed needle counterclockwise one-eighth turn to prevent engine from being too lean at high speeds Tighten packing nut securely to prevent high -speed needle from rotating