Suzuki GSF1200S 2001 Service Manual page 163

• Remove the vacuum inlet cap from the carburetor (for cylinders
#1 or #4).
• Connect one of the carburetor balancer's rubber hoses to this
inlet.
$ 09913-13121: Carburetor balancer
NOTE:
If it is difficult to connect the carburetor balancer's rubber hoses
to the vacuum inlets, slightly move the carburetor assembly back-
ward after loosening the carburetor clamps.
• Start the engine and let it run at 1 750 r/min.
Adjust the engine speed by turning the throttle stop screw.
• Turn the air screw 1 of the carburetor balancer so that the
vacuum pressure causes the steel ball 2 to rise to the center
line 3 of the tube.
• After making sure that the steel ball remains at the center line,
disconnect the hose from the vacuum inlet and connect the
next hose to the vacuum inlet.
• Turn the air screw for this tube until the steel ball 4 is at the
center line of its respective tube.
• Repeat the above procedure on the third and fourth hoses.
The carburetor balancer is now ready to be used to synchronize
the carburetors.
FUEL SYSTEM 4-25