Abstract: An apparatus for mixing fuel and air and providing the mixture to an engine can include an entry conduit, a transfer conduit, and a mounting plate for coupling to an engine. The entry conduit can include a straight channel and an opening for receiving air into the channel. The entry conduit can also include a fuel inlet port disposed through a wall of the entry conduit for receiving fuel into the channel. A venturi valve can be disposed within the straight channel and can include an air-fuel mixing chamber, an inner wall, one or more fuel orifices disposed through the inner wall, and a fuel diffusion chamber fluidicly coupled to the fuel inlet port and the air-fuel mixing chamber. The transfer conduit can be coupled or integrally formed with the entry conduit and include an arcuate internal channel.