Beta Marine Beta 10 Operator's Maintenance Manual page 10

6
Standard Exhaust
High Rise Exhaust
Dry Exhaust System
a) An engine correctly installed in accordance with this
handbook will meet the emission requirements of the
RCD (see back of manual).
b) Keep exhaust systems to a minimum length and have
gradual bends (NOT right angle elbows). Exhaust back
pressure is increased by longer exhaust length and
sharp bends. Back pressure should be measured; with
the complete exhaust system connected and the engine
running at full speed; and should NOT exceed 70 mm
Hg (3.1 inches Hg). The correct measuring point is
before the dry exhaust bellows (at the manifold flange).
We can supply a Manometer kit for testing 'Back
Pressure'.
c) The dry exhaust system installed in a canal boat or work
1
boat should be 1 / " minimum internal diameter.
2
7
If required - a cooling water feed (approx
must be taken from the engine side of the anti-syphon
valve for water lubrication of the cutlass bearing
Anti syphon valve or
T piece fitted here
If a rope cutter is fitted, allow approximately 1/2"
for engine movement, see manufacturer's literature
1 / BSP)
4
*measured on the centre line of the boat
30 cm
minimum
Waterlock
Silencer
Propeller Clearance: between tip of propeller blade and
underside of hull should be at least 10% (some say 15%)
of the propeller blade diameter to avoid 'tip noise'
The engine is fitted with a 1
stub as standard - Valid for exhaust systems up to 3
metres in length. A flexible exhaust bellows and dry
exhaust silencer should be used. It is up to the installer
to work out his own pipe run but care should be taken
as follows:
• Never use a flexible exhaust bellow as a bend, it will
crack, always keep them straight.
• Ensure that rain water cannot enter the exhaust port
and run back down the system, flooding the silencer
and eventually the engine. (See drawings below).
• The system should be lagged if there is any danger of
the crew getting near it.
• A dry exhaust system will give off considerable heat
and suitable ventilation must be provided.
8
Ensure exhaust raises then falls to outlet
8
40 cm
minimum
5 cm
minimum
1
/ " BSP male connector
2
Maximum
seawater level
when heeled*
Normal
seawater
Level