Christini AWD 250, Service Manual

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Carburetor jet needle Carburetor jet needle Carburetor jet needle Carburetor jet needle
The jet needle and jet needle hole together have their greatest effect in the one-
half throttle range. The needle moves in and out of the jet needle hole; since the
needle is tapered, its position in the jet determines the amount of fuel allowed
to flow. There are five grooves in the upper section of the needle where a
circlip fits. This clip locates the needle in the throttle valve and determines its
relative position in the jet needle hole, and provides a rich mixture. Moving the
clip to the top will provide a lean mixture. Change the clip position one step at a
time. The straight area of the needle affects throttle valve response in the small
openings range.
Test runs with the motorcycle
Test runs with the motorcycle Test runs with the motorcycle Test runs with the motorcycle
- Warm up the engine with the carburetor at the standard setting, and inspect the operating conditions of
the spark plug.
- Test-ride the motorcycle with the throttle opened.
Symptoms of improper settings
Symptoms of improper settings Symptoms of improper settings
Symptoms of improper settings
If your motorcycle exhibits one of the following symptoms the changes must be adjusted. Before attempting
any changes, make sure that everything else is in good operating condition.
Check the condition of the spark plug, make sure the ignition timing is correct, service the air cleaner ele-
ment, decarbonize the exhaust tube.
If your machine has run properly up to this point, it is possible that the problem is elsewhere; changing the
carburetor settings in such a case would probably be a waste of time.
- Set the carburetor so that the engine delivers satisfactory power with the throttle valve opened.
- If the air-fuel mixture is too lean, the engine tends to overheat and may be seized. On the other hand, if it
is too rich, the spark plug easily gets wet and causes misfires. The proper mixture varies depending on at-
mospheric conditions. Taking these conditions into consideration, adjust the carburetor settings properly.
NOTE NOTE NOTE NOTE
Keep in mind that the carburetor components that regulate fuel flow and the screw that control the flow of
Keep in mind that the carburetor components that regulate fuel flow and the screw that control the flow of Keep in mind that the carburetor components that regulate fuel flow and the screw that control the flow of
Keep in mind that the carburetor components that regulate fuel flow and the screw that control the flow of
air must be tight.
air must be tight. air must be tight. air must be tight.
Tune-up