Sometimes it takes slightly bending the choke linkage in the right direction and right amount to get the choke butterfly to close completely.this particular model does not have a throttle cable. just a linkage from the carb to the exhaust that is not adjustable
Cub Cadet ST100 25A-262J756 Wheeled String TrimmerPost all Model and serial numbers for the unit and engine so we have a better idea of what you are dealing with.