Hamilton Jet HJ212, Installation And Service Manual, Page: 105 / 198

Installation and Service Manual
Overhaul
Tailpipe Area Dismantling
Refer to drawing: HJ21201000 Base Jet Assembly.

Remove the nuts [17] and spring washers [16] from the studs [30], securing the tailpipe to the intake.

Remove the tailpipe [41] complete with the marine water bearing [2], off the studs [30] and slide the
tailpipe carefully off the impeller. The impeller is now exposed.

Lock the engine or driveline to prevent it turning while removing the impeller nut [10].

Using a large socket wrench, remove the impeller nut [10], ensuring that the mainshaft [1] is supported
during impeller nut removal to prevent overloading of the main bearing [7].

Remove the water bearing sleeve [4].

The impeller can now be withdrawn off the mainshaft.

Remove the impeller key [11] from the key-way in the mainshaft.
Tailpipe, Marine Bearing and Wear Ring Inspection
With the tailpipe [41] removed from the jet unit intake, do the following:

Check the condition of the marine bearing. If it is badly scored it will have to be removed from the
tailpipe and replaced.

Check the wear on the wear ring [37]. This should be evident where the impeller has been running. If
there is evidence of bad wear, by a 0.5mm lip in the wear ring, or there is evidence of corrosion through
or under the wear ring. The wear ring should be replaced.

Using a multimeter, make sure that there is no electrical connection between the wear ring and the
tailpipe casing. This could cause corrosion under the wear ring. The wear ring and insulator should be
removed and replaced.

Check the water off-take filter by removing the bung [36]. Remove any stones in the filter holes.

Check the condition of the o-ring [47] fitted to the bung [36]. Replace if damaged, perished or deformed.

Check for signs of damage or corrosion to the leading edges of the stator blades.

Dress off any burrs as necessary.

Check the anode(s) for wear and replace if necessary. Refer to section: Anode Replacement on page 9-4.
Wear Ring Removal and Replacement
Only replace the wear ring if it is excessively worn, or bulging inwards. This could indicate
corrosion build up underneath the wear ring.
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