Low pressure fuel and air charge forming device for a combustion engine

A throttle body assembly for a combustion engine, comprising:

• a throttle body having a pressure chamber in which a supply of liquid fuel is received, and a throttle bore with an inlet through which air is received;
• a throttle valve carried by the throttle body and having a throttle valve shaft extending through the throttle bore and a throttle valve head connected to the throttle valve shaft so that the throttle valve head is movable relative to the throttle bore to control fluid flow through the throttle bore;
• an actuator having a driving member coupled to the throttle valve shaft to move the throttle valve between a first position and a second position;
• and
• a coupler having an input bore in which part of the driving member is received and an output bore in which part of the throttle valve shaft is received so that the coupler rotationally couples together the driving member and the throttle valve shaft, and the driving member and the throttle valve shaft rotate together, wherein the coupler has an axis and the coupler is formed from a material that permits the coupler to flex or bend along an axial length of the coupler.