2007-2009 Honda TRX300EX TRX300X service manual, Page 96Get this manual
FUEL SYSTEM Set the plastic washer between the valve arm and carburetor body (throttle drum side)Install the return spring by hanging the large end onto the carburetor boss (stopper) and set the throttle link arm over the springInsert the link arm shaft through the link arm, carburetor body, plastic washer and valve armHang the shaft hook to the spring small end Turn the link arm shaft clockwise and set the shaft tab onto the link arm as shown Align the screw holes in the valve arm and shaft, install the screw with the spring washer and tighten it to the specified torque