Installation Manual

N40475 Chapter 4

Page 13

Silencers

In some applications a reduction in noise levels from

the exhaust would be desirable and to that extent, a

silencer can be tted.

The exhaust system ejects the cooling water as

well as silencing the engine’s combustion noise and

removing the exhaust gases. The system must create

minimal restriction to the ow of exhaust gases, known

as back pressure, or the engine may be damaged.

Figure 7 shows an engine sited well above the

waterline (1), with a gradient steeper than 5

to the

back of the boat. The water will run naturally down the

exhaust to the stern. To reduce noise a straightforward

in-line silencer (2) should be used.

Note: The above is used in relation to 15kPa.

Figure 7