Vacuum Switch Valve Hose [A] and its Air Cleaner Hous-
Removed Vacuum Hoses
Install the air cleaner housing [A].
Start the engine and warm it up thoroughly.
Check the idle speed.
If the idle speed is out of the specified range, adjust it.
Do not measure the idle speed by the tachometer of
the meter unit.
While idling the engine, inspect the engine vacuum, using
the vacuum gauge [C].
ZX636B : 24 ± 1.3 kPa (180 ± 10 mmHg)
ZX600K : 22 ± 1.3 kPa (165 ± 10 mmHg)
at Idle Speed 1 300 ± 50 r/min (rpm)
If any one vacuum measurement is not within specifica-
tions, first synchronize the #1 and #2 throttle valves to #3
and #4 throttle valves by using the center adjusting screw
#1: 170 mmHg
#2: 200 mmHg
#3: 165 mmHg
#4: 190 mmHg
With the engine at the correct idle speed, equalize the
highest vacuum of 1 and 2 (example 200 mmHg) to the
highest vacuum of 3 and 4 (example 190 mmHg) by turn-
ing the center adjusting screw [A].
After adjustment, the final vacuum measurement be-
tween the highest throttle valves may not be 200 mmHg
(in this example). The goal is to have the highest two
vacuums between the left (1 and 2) and right (3 and 4)
banks be the same and be within the service limits.
Open and close the throttle after each measurement and
adjust the idle speed as necessary.
Once the throttle valves have been synchronized, inspect
the main throttle sensor's output voltage to ensure proper
operation (procedure is at the end of this section).
PERIODIC MAINTENANCE 2-15