Abstract: A carburetor anti-icing apparatus and method for a marine drive is provided for heating a carburetor to a temperature above that at which ice may form in the idle and progression circuits of the carburetor. Several heaters, heat sources, and methods are disclosed for heating the carburetor. In one embodiment an electrical heating element is mounted to the carburetor body near the fuel orifices which make up the idle and progression circuits. In another embodiment, engine cooling water is circulated through a heater housing mounted to the carburetor body. In yet a further embodiment, engine exhaust from the marine drive is conveyed through the heater housing mounted to the carburetor body. A thermally conductive gasket is used to improve heat transfer. The carburetor anti-icing apparatus and method also improves low speed running performance due to the improved fuel vaporization resulting from the increased temperature in the progression circuit.

Abstract: A keep-back recess for blocking water, which is likely to be transmitted to a throttle valve along an inner peripheral surface of an intake pipe, is formed at an inner surface of a throttle body. The keep-back recess collects and stores water so that the throttle valve is prevented from freezing without leading engine cooling water in the throttle body.

Abstract: A carburetor anti-icing apparatus and method for a marine drive is provided for heating a carburetor to a temperature above that at which ice may form in the idle and progression circuits of the carburetor. Several heaters, heat sources, and methods are disclosed for heating the carburetor. In one embodiment an electrical heating element is mounted to the carburetor body near the fuel orifices which make up the idle and progression circuits. In another embodiment, engine cooling water is circulated through a heater housing mounted to the carburetor body. In yet a further embodiment, engine exhaust from the marine drive is conveyed through the heater housing mounted to the carburetor body. A thermally conductive gasket is used to improve heat transfer. The carburetor anti-icing apparatus and method also improves low speed running performance due to the improved fuel vaporization resulting from the increased temperature in the progression circuit.

Abstract: An internal combustion engine has a carburetor for mixing fuel with air entering through an inlet. A heat exchanger is mounted onto the carburetor air inlet so that heat from the heat exchanger is conducted to the carburetor housing. The heat exchanger has a plurality of channels through which air from an air cleaner pass on the way to the carburetor. An electric heating device attached to said heat exchanger and a first thermostat controls the electric heating device to raise the temperature of the heat exchanger when the fuel-air mixture falls below a given temperature. A second thermostat senses the temperature of the heat exchanger and prevents the temperature from exceeding a level at which a user's skin will blister if the exchanger is touched accidentally. In cold operating environments, the heat exchanger assembly raises the temperature of the air above the dew point, thus effectively lowering the relative humidity.

Abstract: Heating devices are used to prevent icing and deposition of fuel on the throttle valve under adverse operating conditions; these device comprise electrical resistance hot wires applied to the surface of the throttle valve, yet these wires lead to undesired turbulence in the fuel-air mixture flow. As the length of time in operation increases, the efficiency of the hot wires is lessened by corrosion of their surface. These disadvantages are avoided by integrating the heating device with the component to be heated. To this end, the heating device is disposed in an axial bore of the throttle valve shaft. This arrangement is used especially with mixture-compressing internal combustion engines equipped with carburetors or central injection systems.

Abstract: The invention is directed to a handheld, portable tool such as a chain saw equipped with an internal combustion engine mounted in an engine housing. The engine has a carburetor defining an air-intake channel. A heating element is provided which is electrically connected to the generator of the chain saw and mounted on the carburetor in the region of the air-intake channel. The heating element has a positive temperature coefficient and a predetermined temperature region thereby preventing the carburetor housing and the throttle flap from heating to a temperature above a predetermined value. The heating element and the way it is mounted prevents icing at the carburetor in cold weather thereby enabling the engine to run uninterruptedly and uniformly especially when the engine idles.

Abstract: A flow system for an engine-pump assembly utilizes the engine cooling water for heating the engine carburetors to prevent icing thereof and includes a flow indicator providing a visual indication of the condition of the engine's cooling water flow.

Abstract: Disclosed is a carburetor for internal combustion engines which minimizes the effect on the engine of carburetor ice.To overcome the effect of ice build-up the throttle valve on the side adjacent the idle jet, is bent upstream, thus providing a greater opening between the idle jet and the adjacent part of the throttle valve and a lesser opening on the opposite side of the throttle valve at idle and intermediate throttle openings. Increasing the operating angle of the idle jet half of the throttle valve upstream, toward the vertical position, deters the build-up of ice. Furthermore my invention exposes an ice deposit to the incoming fuel-air mixture, causing early erosion of the same and elimination of prolonged operation with over-rich or lean mixtures.

Abstract: A variable venturi-type carburetor comprising a fuel passage which is open to an intake passage. An air bleed passage is connected to the fuel passage. The carburetor comprises an air bleed control valve device for controlling the flow area of the air bleed passage. The air bleed control valve device comprises a bore formed therein, a push rod slidably inserted into the bore for controlling the flow area of the air bleed passage, and a wax valve actuating the push rod. A cooling water passage is formed in the air bleed control valve device so as to surround the air bleed passage and the wax valve.

Abstract: A carburetor for internal combustion engines having a by-pass port for supplying a pilot fuel to an intake passage includes an electric heater disposed adjacent the by-pass port for heating the latter and a heat-insulating material partially covering the electric heater, whereby the heater is partially exposed from the heat-insulating material to locally heat the by-pass port in a quick and effective manner.

Abstract: Disclosed is a carburetor for internal combustion engines having mechanism substantially to eliminate the effect on the engine of carburetor ice. When ice builds on the downstream face of the butterfly valve, on the side adjacent the idle jet, there is such a reduction of pressure at the mouth of the idle jet as to cause fuel starvation in the main jet, thus causing improper fuel air ratios or engine failure. To overcome this, mechanism is provided to vent the idle jet passage to atmosphere whenever the butterfly valve is in position for the main jet to become the primary source of fuel supply. Further, by venting the idle jet as indicated, the presence of ice on the butterfly valve will not produce the heretofore over-rich or lean mixtures, found to exist. Furthermore, such venting is useful for preventing dieseling in automobile engines.

Abstract: A carburetor having means for utilizing the pressurized lubricating oil which has been heated by the engine, to heat the idle mixture adjusting needle valve area and the main fuel jet nozzle area. Divided oil passages are provided within the carburetor structure for circulating the heated oil from the engine to the ice-susceptible areas before returning it to the engine's lubricating system for reheating. Flow adjustment means are provided for regulating the flow through the divided passages.

Abstract: A device for completely vaporizing the fuel delivered to an internal combustion engine so as to minimize the emission of air pollutants. The device includes a heat conducting tubular housing, a heat conducting screen within and coaxial with the housing with an annular space between the housing and the screen, a heat conducting helical coil within the annular space and coaxial with the housing and the screen, and means for heating the helical coil, either electrically, or with heated air. In one form, a diffuser within and coaxial with the screen adjacent the inlet of the housing directs a fuel and air mixture outwardly into contact with the screen, helical coil and housing. In another form, a fuel injecting means within and coaxial with the screen adjacent the inlet end of the housing sprays fuel toward the outlet end of the housing and outwardly against the screen. A de-icer tube communicates with the inlet end of the housing for delivering heated air thereto under icing conditions.

Abstract: Icing troubles with carburetors of two-cycle engines can be effectively avoided by the provision of an engine-lubricating-oil nozzle arranged in the carburetor and opening into the intake air passage therein in a position adjacent to the fuel nozzle in opposing relation to the throttling end of the piston type air throttle valve so that oil films are formed on the exposed surfaces of the throttle valve and the needle valve associated therewith to control the rate of fuel discharge into the intake air passage. Any ice possibly formed on the valve surfaces readily exfoliate, not causing any sticking of the throttle and needle valves in the carburetor.