Alamarin Jet AJ 160, Operation And Maintenance Manual

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15 Operation and Maintenance Manual
Version 1.5 Version 1.5
At planing speeds, a jet boat usually crosses reed fields without difficulty. In difficult
conditions however, clogging may be possible. In boats equipped with a gear box,
cleaning the intake duct is easy because at reverse gear, a back flow is created in the
duct.
2.4. Operating in Reedy Water
THE JET HAS BEEN DESIGNED TO RUN ON REVERSE GEAR
ONLY MOMENTARILY AND ON LOW REVOLUTIONS. A TOO
HEAVY LOAD ON REVERSE GEAR CAN LEAD TO JAMMING
OF THE IMPELLER OR BREAKING DOWN OF HYDRAULICS!
Figure 2.4-1
If clogging occurs on a boat that does not have a gear box, the following procedures are
recommended:
1. Stop the engine. This causes the extraneous objects in the grass rake simply to
drop off.
2. Let the engine run on high revolutions for a few times. This often sucks the
extraneous objects through the jet and cleans it.
3. If the boat is moving forward, raise the boat speed as much as possible and then
shut down the engine. The speed of the boat often sweeps the grass rake clean.
4. Drive the boat on reverse as fast as possible. As the boat moves astern, shut
down the engine and move the deflector control lever to forward position.
This causes water to flow backwards through the jet and usually opens any
blockage whatsoever.
The sleeve shown in figure 2.4-1 on the axle has a left-handed threading. If the engine is
run at too high revolutions on reverse gear, the sleeve may loosen and the impeller may
get stuck against the duct walls.