1978 Johnson 55 HP Outboards Service Manual, Page 117Get this manual
7 Grasp throttle cable casing guide and trunnion nutPull firmly on casing guide to remove backlash from cable and remote controlNOTE Unless backlash is removed before connecting and adjusting throttle cable, engine may not return to consistent idle speedRemove two screws at back of control box and remove upper housing by lifting straight upWith upper housing removed, all components are accessibleLift cam assembly from housingSee Figures 8-15 and 8-168
Position the throttle cable as shown in Figure 8-8Adjust the trunnion adjustment nut on cable until hole in caSing guide slips over throttle lever pinSnap the spring clip up into position to hold casing guide to throttle leverThe throttle cable must be adjusted just tight enough to insure that the engine throttle lever returns to its idle stopIf this cable is too loose, the engine idle speed will be high and inconsistant, causing difficulty shifting out of gearIf it is too tight, the control will feel stiff through the shifting range, and the warm-up lever will tend to move up when shifting to neutral SAFETY WARNING ill order to avoid unnecessary twisting and potential breakage of cable; the throttle cable must be installed so that the clamp and anchor screws are horizontalAlso, the clip on casing guide must be toward bottom of engine and the flat side of caSing guide must be toward the throttle leverSee Figure 8Figure 8-15Cam, Detent Ball and Spring, and Tachometer LeadRemove ball