Carburetor Assy of the Present Invention

Carburetor Assy of the Present Invention

A carburetor assy is a complex piece of hardware that controls the air-fuel ratio and fuel flow to your vehicle's engine. Several different things can go wrong with your carburetor assy that could cause poor performance or even a complete failure of the carburetor. Some common symptoms of a carburetor assy problem are hard starts, lack of power and reduced fuel efficiency. If you notice any of these issues, it's a good idea to get your carburetor assy checked out by a professional.

Prior art carburetors typically consist of a die cast body made of, for instance, aluminum or zinc to which a fuel bowl assembly is secured by threaded fasteners. The die cast body is expensive to manufacture because it requires a great deal of machining to provide numerous passages and apertures. The molded plastic carburetor body of the present invention reduces these costs because the amount of machining required is kept to a minimum.

The molded plastic carburetor assembly of the present invention includes an extruded body, a molded venturi which is inserted into the body and a molded fuel bowl that is secured to the body by means of a spring clip. A throttle shaft bore is provided in the body for receiving a throttle shaft which, when rotated, can control the amount of fuel and air mixture that is drawn through the carburetor assy and into the engine cylinder.

As shown in FIGS. 1 and 2, a venturi insert 22 is mounted in the through bore 20 of the carburetor body. The venturi insert comprises a tubular member having a first end disposed in the well and a second end extending through a radial passage in said body to said through bore thereby axially locating said venturi member.

A nozzle tube 18 extends from fuel bowl 14 through gasket 13 and a nozzle aperture 21 in body 12 to conduct fuel from the bowl into said venturi member. The nozzle tube is resiliently sealed to the fuel bowl by an O-ring disposed between said fuel bowl and the tube first end.

A mixing screw holder is formed in the body of the carburetor with an orifice 84 for receiving the tips of a pair of adjusting screws, each of which has an annular shoulder that acts as a stop so that the screws cannot be driven too far into the orifice and damage the carburetor. Screws 152 and 154 are the idle mixture screw and power mixture screw, respectively. The adjusting screws have self tapping threads so that the mixing screw housing 86 does not need to be provided with threads during molding thereof. The screws have conical tips 153 and 155 which form orifices 156 and 158 in apertures 150 and 151 when they are driven to their limits. This configuration ensures that the desired mixture of fuel and air is emitted from the carburetor assy. The mixing screw holder also has a sealing surface which helps to keep the mixture from leaking out of the carburetor assy during operation.

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