- Robin Generator Service Manual

9-5 CARBURETOR
9-5-l FUNCTION AND STRUCTURE
(1) Float System
The float chamber is located directly under the carburetor.
The float and the needle valves
maintain a constant fuel level inside the float chamber while the engine is running.
The fuel in the tank flows into the float chamber through the needle valve. When a certain
quantity of the fuel enters the chamber the float rises and when the buoyancy of the valve
balances with the fuelin-flow pressure the needle valve is interrupted to keep the fuel at the
correct level.
(2) Pilot System
The system controls the fuel supply for engine speeds ranging from idling to low-speed running.
The fuel flows through the main jet into the pilot jet where the fuel quantity is measured. Then,
the fuel is mixed with air measured in the pilot air jet, and is supplied from the pilot outlet by-
pass to the engine. Fuel for idling is supplied mainly from the pilot outlet.
(3) Main System
The system supplies fuel for medium and high speed operations. The fuel is measured in the main
jet, and then flows into the main nozzle. Air measured in the main air jet mixes with the fuel
from the bleed hole of the main nozzle bursting into the main bore in the form of gas mist. Then
it is again mixed with air inducted through the air cleaner to get appropriate density, and finally
it is supplied to the engine.
(4) Choke System
The choke system helps start the engine in cold weather.
When the choke is closed and the engine is started, the load to the main nozzle increases and
inducts a large quantity of fuel, thus facilitating starting.
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