The throttle cable on the Homelite UT21566 gas trimmer connects the trigger with the carburetor. Without this part, your trimmer will not accelerate. This cable may become detached from either the trigger or the starter housing and will need to be replaced. You can access the throttle cable by removing the control assembly. There are also ignition wires and an “On/Off” switch, which are also connected to the control assembly. You can also service these parts at this time if they are damaged.
Unscrew the three screws holding the control assembly to the shaft. Remove the four screws on the starter housing that hold the shaft to the engine with the screwdriver.
Pull out the shaft from the engine. Remove the Z fitting from the carburetor’s plate and pull out the throttle cable.
Unscrew the four screws holding the two halves of the control assembly together. Pull apart the halves to take the control assembly off the shaft.
Disconnect the two lead ignition wires from the switch with the screwdriver. Pull off the throttle cable and replace. Check the switch, trigger and wires for any damage, and replace if necessary.
Reassemble the parts in reverse order. Connect the ignition wires to the switch. Hook the throttle cable to the trigger’s spring. Secure the control assembly halves together around the shaft. Reattach the throttle cable to the carburetor’s plate.
Re-screw the four starter housing screws to secure the shaft. Tighten the screws holding the control assembly to the shaft.