Section 3.4

CARBURETOR

GENERAL INFORMATION

Proper engine performance depends on the carbure- tion system. The use of clean, fresh gasoline and a well-maintained air cleaner are extremely important to proper operation, as well as engine reliability and power.

Most causes of carburetion problems are related to the use of stale, gummy fuel and the ingestion of dirt. Before servicing the carburetor, be sure to check for evidence of these conditions. Gasoline that is left in the fuel lines for long periods can form gum or varnish deposits that will adversely affect carburetor opera- tion.

NOTE: A commercial fuel stabilizer (such as STA- BIL®) will minimize the formation of um deposits during storage. Add the stabilizer- to the gasoline In the fuel tank or In the storage container. Follow the ratio recommended on the stabilizer contain- er. Run the engine for about 10 minutes after adding stabilizer, to allow It to enter the carbure- tor. "STABIL®" Is a brand name fuel stabilizer that can be purchased In most automotive repair facili- ties or in lawn and garden centers.

DESCRIPTION

The carburetor used on GV-220 engines is a float type with fixed main jet. Carburetor throttle position and engine speed are controlled by an electric stepper motor. The stepper motor moves the throttle in response to signals received from the A6060 circuit board. The circuit board senses load voltage, establish- es the correct engine speed to obtain correct voltage and delivers an output signal to the stepper motor. The stepper motor adjusts the engine throttle to change engine speed and establish correct output voltage.

Figure 1. Carburetor

CARBURETOR OPERATION

FLOAT OPERATION:

A hollow plastic float maintains fuel level in the float bowl. As fuel is used, the float moves downward to move an inlet needle valve off its seat.

When the needle valve moves off its seat, fuel can flow into the bowl. As the fuel level rises, the float moves upward to force the needle valve against its seat and stop the flow into the bowl.

Figure 2. Carburetor Sectional View

CHOKE POSITION:

The choke valve is closed to restrict the flow of air into the engine. As the engine cranks, air pressure in the cylinder is reduced. Since the air intake passage is partially blocked by the choke valve, fuel is drawn from the main nozzle and from the idle discharge port. This creates the very rich fuel mixture required for starting a cold engine.

IDLE OPERATION:

The throttle valve is nearly closed to shut off the fuel supply from all ports except the primary idle fuel dis- charge port. Engine suction then draws fuel only from that port.

HIGH SPEED OPERATION:

The throttle valve is wide open. This allows a large volume of air to pass through the carburetor at a high velocity. The high velocity air flow past the carburetor venturi results in a drop in air pressure at the venturi throat. This reduced air pressure draws fuel through the main nozzle that opens into the venturi which then mixes with the air in the air passage.

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Generac Power Systems 941-2, 940-2 service manual General Information, Description, Carburetor Operation
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941-2, 940-2 specifications

Generac Power Systems has established a strong reputation in the field of backup power solutions, particularly with its innovative products like the Generac 940-2 and 941-2 generator systems. These generators are designed to provide reliable power during emergencies, ensuring that homes and businesses can maintain operations seamlessly when grid power is disrupted.

One of the standout features of the Generac 940-2 and 941-2 models is their robust engine performance. Both generators utilize Generac’s patented engines, known for their durability and efficiency. These engines are built to withstand the most demanding conditions while providing a consistent power output. This reliability is crucial for users who depend on uninterrupted power supply for essential appliances and equipment.

In terms of technologies, the Generac 940-2 and 941-2 are equipped with advanced automatic transfer switch capabilities. This technology allows the generators to automatically start and supply power within seconds of an outage. This quick response time helps to ensure that critical systems remain operational without noticeable interruptions, which is vital for businesses and households alike.

Another important characteristic of these models is their user-friendly interface. The generators come with an intuitive digital controller that provides real-time information on power usage, system status, and maintenance needs. This technology makes it easy for users to monitor their generators and ensure they are always ready for an emergency.

The design of the Generac 940-2 and 941-2 also emphasizes noise reduction and aesthetic appeal. These units are engineered for quieter operation compared to traditional generators, making them suitable for residential areas. Their sleek appearance also fits well with modern home exteriors, enhancing rather than detracting from the property’s visual appeal.

Furthermore, these generators offer flexible fuel options, with the ability to run on natural gas or propane. This versatility allows users to choose the fuel source that best meets their needs, contributing to energy efficiency and lowering overall operating costs.

In summary, the Generac Power Systems 940-2 and 941-2 are exceptional generators that combine powerful performance with innovative technologies. Their automatic transfer switch capabilities, user-friendly controls, noise reduction features, and flexible fuel options make them an excellent choice for anyone seeking reliable backup power solutions. With these generators, users can rest assured knowing they have a dependable energy source ready when they need it most.
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