The twist-grip on your Johnson outboard's tiller controls the motor's speed, like the accelerator in your car. When the twist-grip gets "sloppy" or "out of whack," the problem is that the throttle cable has slipped or stretched and developed "backlash," or slack. You can repair the problem by adjusting the cable, pulling the slack from it and reconnecting it in its new position. Keep the backlash out of your cable and you can enjoy precise throttle control.
Turn to the motor. Grasp the idle speed adjustment knob. Turn it counterclockwise until it reaches the "dead slow" idle position.
Attach the throttle cable to the top hole in the throttle lever arm. Insert the pin and fasten it in place with the cottar clip from the throttle repair kit. The clip must be parallel to the lever's raised ridge.
Continue to hold the throttle grip in the "dead slow" position. Leave the idle speed screw on its stop and pull on the throttle cable toward the cable bracket to remove all slack from the cable. Align the cable bracket with the mounting screw hole forward of the carburettor.
Thread the cable through the attachment point to the linkage twice, wrapping the cable toward the end of the cable. Install the bracket to the manifold, placing with the flat washer between the manifold and the bracket. Thread the bracket retaining bolt into its bore and tighten the bolt to 36 inch-pounds with a torque wrench.
Set the cable retainer plate in place. Tighten the bolts snugly. Rotate the throttle grip at least three times to verify the idle speed screw touches the stop when the throttle is in the slowest speed position.
If the throttle grip is difficult to twist or twists too easily, look for a screw, recessed into the underside of the handle near the handle's hinge. Turn the screw clockwise to tighten the handle. Turn the screw counterclockwise, and it becomes easier to twist the throttle grip.