Hamilton Jet HJ212, Инструкция по установке и обслуживанию

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Appendix
Installation and Service Manual
Aerated Water
Under certain conditions, some hulls may feed aerated water into the intake of the jet units.
When operating in areas where the water may be excessively aerated (e.g. fast flowing rapids or surf), the
following points should be noted:

There may be a loss in thrust due to the jet unit pumping a significant amount of air instead of water.

The impeller may unload suddenly causing the engine RPM to fluctuate wildly.
When these symptoms occur, reduce engine speed until the jet unit maintains a steady RPM and thrust.
Blockages (Debris in the Jet Unit)
Avoiding blockages
Water weed, sticks, and other debris will not normally block or harm the jet unit.
Steer around debris if possible, as any obstruction of the intake screen, impeller or tailpipe stator vanes can
affect the jet unit's performance.
Detecting blockages
In water with lots of debris, it may be necessary to clear the intake screens and impellers before each run.
In many cases the debris is picked up while the vessel is moored.
Any of the following can indicate a blocked jet unit:

Engine RPM increases.

Lack of jet thrust (vessel speed drops).

Abnormal noise and vibration from the jet unit.
Clearing blockages
To clear a blocked jet unit try the following:

Slowing or stopping the engine driving the blocked jet unit will often clear the blockage. This works best
when the vessel is still moving forward at speed.

Trailer the vessel and clear the blockage from underneath.

If seaweed is blocking the intake screen, the optional screen rack may be used over the rear of the
transom to clear the seaweed. Refer to drawing: HJ21209004 Hand Held Screen Rake.

Remove the inspection cover on the intake and manually clear the blockage..
Inspection Covers
Extreme care is required whenever inspection covers are removed, as water may enter the
vessel through these openings.
Inspection cover nuts should not be fully removed until the inspection cover has been
loosened, so that if the water level is higher than expected, the inspection cover can be re-
secured.
Never leave inspection covers removed without continuous monitoring of the water levels.
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