Dual fuel carburetor

A dual fuel carburetor, comprising a carburetor body, a main jet pipe, and a float chamber housing covered on the carburetor body to form a float chamber, a main metering jet being provided on a fuel inlet end of the main jet pipe, and a needle valve device being formed between the main metering jet and the float chamber to control their connection or disconnection, the needle valve device comprising a pushing needle and a needle valve base which has a valve base hole cooperated with the pushing needle and a fuel inlet communicated with the float chamber, the pushing needle being movably inserted in the float chamber housing along an axis thereof, and a window being formed at a bottom of the float chamber housing to allow the pushing needle to pass through, wherein the needle valve device further comprises a sealed corrugated sleeve positioned around the pushing needle, which has a first end hermetically connected with the pushing needle and a second end hermetically connected with the float chamber housing, a driving spring is positioned around the pushing needle to urge the pushing needle to block the valve base hole, and the pushing needle has a driving end which is extended out from the float chamber housing and is opposite to that end cooperated with the valve base hole.