Abstract: A structural improvement on a carburetor for motorcycles, and more particularly relating to a carburetor provided with an oil re-atomizing device intends to ensure an almost complete atomization of injected oil before delivery into a combustion chamber of an engine. Near the middle of a horizontally extended air passage of the carburetor is disposed a smoothly enlarged section having an increasingly expanded diameter so as to permit a re-atomizing device to be mounted to the end of the section. The re-atomizing device is made up of a cone-shaped head portion and a circular supporting bracket that are fixed together by a screw. Oil sucked into the air passage via a needle controlled oil supply passage is brought into direct collision against the round ended cone-shaped head portion of the re-atomizing device.