1988 Johnson/Evinrude "CC" 40 thru 55 Models Service Manual, Page 61Get this manual
Synchronization and Linkage AdjustmentsTiller Handle Models I Note lit is important that this step-by-step procedure be followed in sequence and be performed exactly as written to ensure consistent engine idling and smooth operation throughout the RPM range Throttle Cable Adjustment
1As you face the steering handle, turn the idle speed adjustment knob counterclockwise to minimum slow speed position Be sure throttle cable bracket is secured to the powerhead
t=.J using the forward bracket hole
3Back out the idle speed screw screw
and wide open stop
4 Turn the twist grip to full open and to full closed positionsCheck the clearance between the roller and end of the cam slotThe roller should be approximately 1 in(6 mm) away from both ends of slot5If adjustment is necessary, loosen jam nut and rotate thumb wheel to obtain correct adjustmentTighten jam nut after correct adjustment is obtained