Operating In Freezing Temperatures; Operating In Saltwater Or Polluted Water; Operating In Shallow Water; How The Jet Drive Operates - Mercury 40 JET FOURSTROKE Operation, Maintenance & Installation Manual

Check for debris around the rudder and reverse gate which may jam or
hinder operation.
Before launching, examine the jet drive water intake for obstructions
which may prevent pumping of water.
Ensure the driveshaft bearing on the jet drive is lubricated.

Operating in Freezing Temperatures

If there is a chance of ice forming on the water, the jet drive should be removed
and drained completely of water. If ice should form at the water level inside the
outboard driveshaft housing, it will block water flow to the engine causing
possible damage. Do not start the engine until the ice is clear.

Operating in Saltwater or Polluted Water

If the boat is kept moored in the water, always tilt the outboard so the water
intake is completely out of the water (except in freezing temperatures) when not
in use.
Wash down the outboard exterior and flush out the exhaust outlet of the jet
drive with fresh water after each use. Each month, spray Mercury Precision or
Quicksilver Corrosion Guard on external metal surfaces.
NOTE: Do not spray on corrosion control anodes as this will reduce the
effectiveness of the anodes.

Operating in Shallow Water

The life of the impeller and water intake can be greatly increased by avoiding
the intake of sand and gravel. The intake suction will act like a dredge when the
water intake comes close to the bottom. It is better to stop the engine and drift
up to shore when landing, and to shove off with an oar when leaving. The
engine can idle through areas of water less than 61 cm (2 ft) deep, but there
should be more than 61 cm (2 ft) of water under the boat when increasing
speed to reach full plane.
Once the boat is on plane, the boat speed will prevent the ingestion of gravel
and other debris from the bottom. The suction is still present, but the water
intake passes too quickly over the bottom to allow debris to be drawn into the
water intake.
When boating through shallow water areas, choose a course of travel that
avoids sharp rocks and other underwater obstacles that could damage the
boat. Running the boat through these areas on full plane may be helpful as the
boat will be riding higher in the water. If the boat gets stuck on the bottom,
immediately stop the engine and move the boat to deeper water.

How the Jet Drive Operates

A jet driven boat has substantially different handling characteristics compared
to a propeller driven boat. It is recommended that the operator adjusts to these
characteristics by experimenting in open water at both high and low speeds.
OPERATION
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