Hamilton Jet HJ241, Manual

Page: 80 / 202

7.2
7 FAULT FINDING
7.1 J
ET
U
NIT
F
AULTS
HJ-241 / HSRX
5 Excessive high pitched rattling, or rattling whine coming from the Jet Unit.
Blockage of the Jet Unit.
Faulty Thrust Bearing.
Cavitation is occurring.
The Blockage must be removed.
Inspect and repair the Thrust Bearing.
Blocked Intake Screen.
Check for Blunt or damaged Impeller.
Excessive Impeller tip clearance.
Wrong type of Impeller fitted.
Vessel overloaded.
Weight too far aft.
Bad weather or sea conditions.
Poor installation of Jet Unit into vessel.
Sect. 2.9
Sect. 9.6
Sect. 2.8
Sect. 2.9
Sect. 9.7.6
Sect. 9.5.2
Refer Draw-
ing
HJ-241-
03-001
Impellers
Sect. 5
6 Bad vibrations.
Blockage of the Jet Unit.
Worn Marine Bearing, or Marine
Bearing water drain hole in the Tail-
pipe blocked.
Something caught in the Impeller.
Worn driveshaft universal joints.
The blockage must be removed
Check and clear the water drain hole in the
Tailpipe Cone, inspect and repair the
Marine Bearing.
Check through Inspection Hatch, clear
obstruction.
Inspect and repair the driveshaft as per
manufacturer’s recommendations.
Sect. 2.9.3
Sect. 9.7.1
Sect. 8.5.1/1
Refer to
Manufactur-
ers Manu-
als.
7 Engine revolutions gradually increasing over a period of time. Take off performance poor.
Worn or blunt Impellers.
Excessive Impeller tip clearance.
Inspect and repair the Impeller as well as
the Wear Ring.
Inspect and repair the Impeller as well as
the Wear Ring.
Sect. 8.5.1/
17a) &
17b).
Sect. 9.7
8 Sudden increase in engine revolutions with no noticeable decrease in thrust.
Air ingestion, or cavitation.
Faulty tachometer.
See No.5 above.
Repair tachometer.
9 Excessive engine revolutions, noisy Jet Unit and aerated water from Nozzle.
Screen blocked with wood or debris
or rope through Screen and wrapped
around shaft.
Object jammed in Stators and / or
Impeller. Remove blockage.
Remove object.
Sect. 8.5.1/1
& Sect. 2.9
Table 5: Jet Unit Faults
NO
SYMPTOMS
POSSIBLE CAUSE SOLUTION REFER