4-10 ENGINE TOP END
Clean Air System (US, CH, AT, KR, C2 ∼ CA, DE & C6 ∼ EUR, FR)
Vacuum Switch Valve Test
Using the vacuum gauge and a syringe, inspect the vac-
uum switch operation as follows.
Remove the vacuum switch valve.
Connect the vacuum gauge [A] and syringe [B] or fork oil
level gauge to the vacuum hoses as shown.
Air Flow [C]
Special Tools - Vacuum Gauge: 57001-1369
Fork Oil Level Gauge: 57001-1290
Gradually raise the vacuum (lower the pressure) applied
to the vacuum switch valve, and check the valve opera-
tion. When the vacuum is low, the vacuum switch valve
should permit air to flow. When the vacuum raises to
valve closing pressure, it should stop air flow.
Low Vacuum [D]
Secondary Air Flow [E]
If the vacuum switch valve does not operate as described,
replace it with a new one.
To check air flow through the vacuum switch valve, just
blow through the air cleaner hose.
Vacuum Switch Valve Closing Pressure (open → close)
Standard: 57 ∼ 65 kPa (0.58 ∼ 0.66 kgf/cm², 8.3 ∼ 9.4
High Vacuum [A]
Secondary air cannot flow [B]
Clean Air System Hose Inspection
Be certain that all the hoses are routed without being flat-
tened or kinked, and are connected correctly to the air
cleaner housing, vacuum switch valve, and air suction
If they are not, correct them. Replace them if they are