In at least some implementations, a charge forming device includes a body defining at least part of a first passage, a throttle valve movable relative to the first passage between an idle position and a wide open position, an air bleed passage communicated with the first passage, and a control valve. The control valve may be arranged in the air bleed passage to selectively inhibit or prevent air flow to the first passage from the air bleed passage. And the control valve is moveable between a first position and a second position in response to movement of the throttle valve wherein greater air flow is permitted from the air bleed passage to the first passage in the body when the control valve is in the second position than when the control valve is in the first position.

In at least some implementations, a charge forming device includes a body defining at least part of a first passage, a throttle valve movable relative to the first passage between an idle position and a wide open position, an air bleed passage communicated with the first passage, and a control valve. The control valve may be arranged in the air bleed passage to selectively inhibit or prevent air flow to the first passage from the air bleed passage. And the control valve is moveable between a first position and a second position in response to movement of the throttle valve wherein greater air flow is permitted from the air bleed passage to the first passage in the body when the control valve is in the second position than when the control valve is in the first position.

A carburetor, a method of assembling a carburetor, and a method of operating an engine. The carburetor may generally include a housing defining a pump portion and a metering portion; and a maintenance port in communication with the pump portion and the metering portion to allow direct introduction of an additive through the maintenance port and into the pump portion and the metering portion.

A carburetor, a method of assembling a carburetor, and a method of operating an engine. The carburetor may generally include a housing defining a pump portion and a metering portion; and a maintenance port in communication with the pump portion and the metering portion to allow direct introduction of an additive through the maintenance port and into the pump portion and the metering portion.

In an automotive carburetor, the time delay in the response of the engine to the change in the cross sectional area of the air passage is minimized, and a high level of freedom in selecting the communication cross section area of the air passage and the air fuel ratio for the given load of the engine. The carburetor (1) comprises a fuel passage (13) including a fuel nozzle (16) for supplying fuel to the intake passage, a first air passage (14) communicating with the fuel passage to supply air to the fuel passage, a variable communication unit (21, 41) provided in a part of the first air passage and moveable between an open position for communicating the first air passage and a closed position for shutting off the first air passage and a switch mechanism (22, 43) for moving the variable communication unit between the open position and the closed position in dependence on a load of the engine.

In an automotive carburetor, the time delay in the response of the engine to the change in the cross sectional area of the air passage is minimized, and a high level of freedom in selecting the communication cross section area of the air passage and the air fuel ratio for the given load of the engine. The carburetor (1) comprises a fuel passage (13) including a fuel nozzle (16) for supplying fuel to the intake passage, a first air passage (14) communicating with the fuel passage to supply air to the fuel passage, a variable communication unit (21, 41) provided in a part of the first air passage and moveable between an open position for communicating the first air passage and a closed position for shutting off the first air passage and a switch mechanism (22, 43) for moving the variable communication unit between the open position and the closed position in dependence on a load of the engine.

In at least some implementations, a charge forming device includes a body defining at least part of a first passage, a throttle valve movable relative to the first passage between an idle position and a wide open position, an air bleed passage communicated with the first passage, and a control valve. The control valve may be arranged in the air bleed passage to selectively inhibit or prevent air flow to the first passage from the air bleed passage. And the control valve is moveable between a first position and a second position in response to movement of the throttle valve wherein greater air flow is permitted from the air bleed passage to the first passage in the body when the control valve is in the second position than when the control valve is in the first position.

In at least some implementations, a charge forming device includes a body defining at least part of a first passage, a throttle valve movable relative to the first passage between an idle position and a wide open position, an air bleed passage communicated with the first passage, and a control valve. The control valve may be arranged in the air bleed passage to selectively inhibit or prevent air flow to the first passage from the air bleed passage. And the control valve is moveable between a first position and a second position in response to movement of the throttle valve wherein greater air flow is permitted from the air bleed passage to the first passage in the body when the control valve is in the second position than when the control valve is in the first position.

A carburetor comprises a rotation-typed control valve which opens or closes a second bleed air passage according to an opening degree of the throttle valve. The control valve includes an upper end portion of a valve stem, and in a projection plane orthogonal to an axis of an aspirating channel, a first bleed air passage is arranged on one side of the valve stem, an upstream-side passage portion starting from the control valve of the second bleed air passage is arranged on an upper side of the aspirating channel, a downstream-side passage portion starting from the control valve of the second bleed air passage is arranged on the one side of the valve stem, and a downstream end of the downstream-side passage portion is connected to a midway portion of the first bleed air passage.

A carburetor comprises a rotation-typed control valve which opens or closes a second bleed air passage according to an opening degree of the throttle valve. The control valve includes an upper end portion of a valve stem, and in a projection plane orthogonal to an axis of an aspirating channel, a first bleed air passage is arranged on one side of the valve stem, an upstream-side passage portion starting from the control valve of the second bleed air passage is arranged on an upper side of the aspirating channel, a downstream-side passage portion starting from the control valve of the second bleed air passage is arranged on the one side of the valve stem, and a downstream end of the downstream-side passage portion is connected to a midway portion of the first bleed air passage.