Cobra 2005 cm50 Service Manual page 72

• Before making any carburetor jetting changes verify that:
o You are using the proper fuel and oil
o The fuel is fresh and uncontaminated
o The oil and fuel have been mixed in the proper ratio
o The carburetor is clean (no plugged jets)
o The air filter is properly clean and oiled
o The float height is within proper specification (proper measuring technique
is described later in this section)
NOTE:
Perform all jetting changes on a motorcycle that has been warmed up to proper
operating temperature.
The carburetor on your Cobra motorcycle is quite adjustable. Figure 59 shows
its range of adjustment and in particular what adjustable component affects what
range of operation (specifically throttle position).
FUEL SCREW ADJUSTMENT:
The fuel adjustment screw is located on the left side of the carburetor. It is the
smaller of the two adjustment screws and requires the use of a small flat blade
screw driver for adjustment. After adjusting for maximum idle speed, use the idle
screw to adjust the desired idle speed.
NOTE:
If the fuel screw requires more than 3 turns out, replace the pilot jet for one that is
one size richer (larger number) then readjust the fuel screw.
IDLE ADJUSTMENT:
The idle speed screw is located on the left side of the carburetor. It is the larger
of the two screws on the side of the carburetor and is unique with its knurled
head for easy fingertip adjustment. To raise the idle, turn the screw in, clockwise,
(in 1/4 turn increments) and rev the engine after each adjustment. To lower the
idle, turn the screw counter-clockwise.
Figure 59
Adjust for maximum idle speed
Adjust for desired idle speed
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