Mercury 250 Jet, Руководство по установке

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250 HP JET DRIVE INSTALLATION MANUAL
Page 42 90-10240040 DECEMBER 2003
Aft View
a
b
c
d
e
f
g
h
i
j
k l
m
n
a - Alternate Installation – If rubber hosing is to be used for connection between
the expansion chamber and the muffler, a inner sleeve made of 6061-T6, 14 ga.
aluminum tubing must be used as a liner and secured with 2 stainless steel
hose clamps p/n 54-815504 or equivalent. Sleeve should be flared to fit up to
the expansion chamber outlet so as to protect this region from exhaust gas.
b - Typical Recommended Installation – 54-815504 256 stainless steel clamp or
equivalent. All exhaust hoses and/or tubes must be secured with 2 clamps at
each connection.
c - Mufflers may be mounted using straight piping.
d - 25
°
outlet angle of expansion chamber.
e - 15.2 cm (6.0 in.) minimum.
f - Reference maximum practical.
g - 25
°
maximum from horizontal.
h - Optional exhaust outlet cover.
i - 5.1 cm (2.0 in.) minimum.
j - 10 2 cm (4.0 in.)
k - To minimize the back flow of exhaust gases into the cockpit or interior of boat,
the exhaust termination should be located as far outboard of the centerline as
practical.
l - Final system installation shall be reviewed by a MERCURY Field Representative
using a modified expansion chamber to ensure back pressure does not exceed
10.3 kg (1.8 psi) at 304.8 cm (1000 ft) above sea level or less. This test needs to
be performed with the boat in the water and under way. No special loading of the
boat is required. However, the engine must be capable of reaching the specified
W.O.T. engine speed. Maximum RPM must be verified using an accurate service
tachometer.
m - Exhaust system components should be rubber mounted, independently sup-
ported and restrained to minimize noise transmission to the boat and stress on
exhaust system components.
n - 10
°
minimum angle from expansion chamber outlet to muffler inlet.