Beta Marine BV1903 Operator's Maintenance Manual page 25

Typical Yacht Installation
Maximum sea water level when healed
Allow at least 10% of
propeller diameter for tip
clearance to hull
WARNING:
(1) One of the most common problems with engine installation is water entering the exhaust
manifold from the exhaust system by syphoning. This can occur when the point of water
injection (X) on the engine is close to or below the water line. Water entering the pistons
can cause bent con rods, emulsified engine oil and a wrecked fuel pump! Its best
avoided!
(2) The diagram shows a typical installation. It is essential that the small black rubber hose
connecting the heat exchanger with the injection bend is removed and replaced by a
hose marked 'a'. This must be of sufficient length to supply either a T piece or an anti-
syphon valve sited at least 300mm (12 inches) above the water line and on the centre
line of the boat. The pipe then returns to the injection bend and the sea water is
pumped down the exhaust pipe.
(3) The exhaust back pressure should not exceed 3.1 inches of Hg.
(on the centre line of the boat)
Normal sea water level
300mm minimum
If a rope cutter is fitted, allow approximately ½" for
movement of engine, see manufacturer's literature
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