Honda WX15T, Manual

Page: 31 / 100

3-12
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MAINTENANCE
PUMP INLET VALVE CHECK
Remove the inlet pipe [1] (page 9-3) .
Check the pump inlet valve [2] for damage or excessive
wear and replace if necessary.
PUMP VACUUM TEST
Test Procedure
Install thread tape or sealant to the vacuum gauge
and install in the base plate.
Position a garden hose [1] into the discharge port so
a steady stream of water flows during the test.
Start the engine, position the throttle lever in the
FAST position and allow the engine to warm up for
several minutes.
Adjust the throttle lever to the maximum position.
Position the vacuum tester [2] against the suction
port to obtain the vacuum reading.
MINIMUM VACUUM : 22 in.Hg at sea level
Vacuum reading will decrease by approximately 1
in.Hg per 1000 ft increase in elevation.
Shut off the engine and confirm the vacuum gauge
reading remains steady. This verifies the intake
flapper is sealing.
Test Results
If the vacuum gauge does not remain steady after
shutting off the engine, remove any fittings from the
suction port (if installed) and retest. If the vacuum
gauge is still unsteady, disassemble and inspect the
flapper for wear or damage.
A vacuum reading below 22 in.Hg (at sea level)
indicates a problem with the pump. If the vacuum
reading is low, inspect the:
• Impeller and volute for damage or wear
• Impeller/volute clearance
• Mechanical seal for damage
• Pump case housing and O-rings for damage or leaks
If the pump does not prime, but the vacuum reading is
good, there is likely an air leak in the suction hose or
fittings, or the suction head is too high.
[1]
[2]

[2]
[1]
25
30
1
0.8
BAR
100 x Kpa "Hg
0.6
0.4
0.2
0
20
15