Problem situations
Operation and maintenance manual
KHO/340/EN/1.0.0.
37
5.2. Ventilation
Ventilation produces similar symptoms and sounds like cavitation (section 5.1.
, page 35), but is caused by different reasons.
Ventilation is created when air gets into the intake duct. The air causes the
impeller to lose grip and the thrust weakens.
Ventilation can be caused by the following, for example:
• The inspection hatch cover is open or the seal is damaged.
Close the inspection hatch if it is open. Change the seal if it is damaged
(section 4.5.
Seals
• Air gets into the intake duct, for example due to an excessively low v angle
or lifting strakes placed too close to the intake duct.
In this case the jet must be reinstalled. Consult the boat's retailer.
• During installation, places accordant with the instructions have not been
sealed.
In this case, the sealing must be done again. Consult the boat's retailer.
5.3. Clogged jet
Driving among water plants or in ice sludge can clog the jet. If this happens,
the blockage can stop the boat from moving.
With these simple instructions it is possible practically without exception to
clean very difficult blockages from the jet. Unlike with other propulsion units,
in boats equipped with a jet the engine stops very rarely as a result of a water
plant blockage. However, ice sludge can clog the jet so badly that the blockage
cannot be removed without lifting the boat out of the water.
Boats equipped with a gearbox
In boats equipped with a gearbox, cleaning the jet is easy because in reverse
gear a back flow is created in the intake duct.
Cleaning the jet:
1. Put the gear in reverse.
2. Use some acceleration to detach the blockage.
Summary of Contents for AJ 340
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Page 10: ...The jet propulsion unit Operation and maintenance manual 6 KHO 340 EN 1 0 0 ...
Page 18: ...Operation Operation and maintenance manual 14 KHO 340 EN 1 0 0 ...
Page 38: ...Maintenance Operation and maintenance manual 34 KHO 340 EN 1 0 0 ...
Page 44: ...Problem situations Operation and maintenance manual 40 KHO 340 EN 1 0 0 ...