Westerbeke WPDS-20 Technical Manual page 106

REISSUED:
SUBJ ECT:
MODEL:
DISTR:
WESTERBEKE
SERVICE BULLETIN
H81
October 3, 1975
Hydro-Hush Muffler Installation
All
All
The diagram on the reverse side shows a proper installation of the Hydro-
Hush stainless steel muffler.
Make sure installation is such that water cannot enter engine at any
anqle of heel or pitch.
Muffler remains aporoximately twenty-five percent full of water after
engine is shut down with maximum thirty-three inch lift used.
Muffler must be installed as close to fore-aft centerline of boat as
possible.
There must be an unblocked vent to atmosphere at the high point of the
sea water circuit (where it nasses above the waterline) to break the
vaccuum which would encourage siphoning through the sea water circuit
uoon engine shutdown. Such siphoning would fill the engine with sea
water throuqh its exhaust. Pipe the air vent with aooroximately
3/16
copper tubing to discourage water flow through it when the engine is
running. If water flows throuqh the air vent when the engine is running,
oioe it over the side or into the transon exhaust outlet. But be sure
it will drain upon engine shutdown and function properly as a siphon break
by venting the sea water circuit to atmosphere.
Use as few right angle fittings as possible. If there is any question as
to back pressure, check your engine manual.
Exhaust line diameters indicated are minimums. Refer to enqine manual for
snecifics regardina run lengths and sizes greater than indicated.
The installation tips given are to be used as a guide only. We cannot
be resoonsible in any way for muffler installation. We presume basic
understanding of good marine practice on the part of the installer.
V7
J
H WESTERBEKE CORP· AVON INDUSTRIAL PARK· AVON. MASS 02322 US A . TELEPHONE 617 588·7700 TELEX 92·4444· CABLE WESTCORP
PN 19468 10/3/75
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