8B-2 Disassembly And Reassembly - Robin EH09D Service Manual

8b-1-2 PILOT SYSTEM
The pilot system feeds the fuel to the engine during idling and low-speed operation.
The fuel is fed through the main jet to the pilot jet, where it is metered, and mixed with the air metered by
the pilot air jet. The fuel-air mixture is fed to the engine through the pilot outlet and the bypass. At idling
speed, the fuel is mainly fed from the pilot outlet.
8b-1-3 MAIN SYSTEM
The main system feeds the fuel to the engine at medium and high-speed operation. The fuel is metered
by the main jet and fed to the main nozzle. The air metered by the main air jet is mixed with the fuel
through the bleed holes in the main nozzle, and the mixture is atomized out of the main bore. It is mixed
again with the air taken through the air cleaner into an optimum fuel-air mixture, which is supplied to the
engine.
8b-1-4 CHOKE
The choke is used for easy starting when the engine is cold. When the starter is operated with a closed
choke, the negative pressure applied to the main nozzle increases and draws more fuel ; thus richening
the mixture and making starting the engine easier.

8b-2 DISASSEMBLY AND REASSEMBLY

Apart from mechanical failures, most of carbure-
tor troubles are caused by an incorrect mixing
ratio, which may arise mainly due to a clogged up
air or fuel passage in jets, or fuel level variations.
In order to assure proper flow of air and fuel, the
carburetor must be kept clean at all times. The
carburetor disassembly and reassembly proce-
dures are as follows.
8b-2-1 THROTTLE SYSTEM
(1) Remove the philips screw q q q q q and throttle valve
w w w w w , and pull out the throttle shaft e e e e e .
(2) The spring r r r r r can be taken out by removing
the throttle stop screw t t t t t .
*Be careful not to damage throttle valve rim.
1 2 3
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15
17
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21
13
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12
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7
6
8
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5
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Fig. 8-6