Onan MDJF Series Operator's Manual And Parts Catalog page 13

IMPORTANT: DO NOT ,USE SCOOP TYPE WATER INLET
FITTINGS when installing an Aqualift mullIer. Forward facing
scoops develop su fficient ram pressure to force water past
the set's water pump, £looding the exhaust system where it
may flow back, flooding the engine cylinders. This can
happen only
if
the electri
c
set is not
running
and boat is
underway.
1. Secure the muffler to the predetermined location (within
ten-feet of the engine exhaust outlet) using "L"
brackets (Figure 6) Or other suitable mounting devices
such as wood blocks
or
metal straps. Flexible mounts
. may be used if so desired. Allow for air passage under
muffler to prevent condensation.
UL" BRACKET
~ ~~H~~SHER
(MINIMUM
lSI-
NUT BASE'
OF 3) ~-
FIGURE 6. SECURING :THE MUF FLER
~ Do not drill holes high.er tha.n. one inch
. CA above the extreme lower edge of the
muffler when installing mounts.
2. Connect the .f'xhaust lille( 11/2")to the marine elbow on
the engine and to tre exhaustiqlet on the muffler. The dis ­
tance from the base of the muffler to the upper elbow on
the exhaust tubingfrom the muffler outlet must not exceed
fourcfeet (see Figure 3 ) . ' ..
11
SHORT NIPPLE--..
DOUBLE TAPPED
TANK BUSHING
LONG NIPPLE
r .
(INSIDE
............. MUFFLER)
OUTLET
I
.~
NOTE: LONG NIPPLE GOES INSIDE TANK
FIGURE
7:
AQUA LIFT MUFFLER
3. Connect the exhaust line to the muffler outlet and to. th'e
upper elbow. A :onventional automobile tail-pipe hanger
bracket may be used to hang the upper elbow. Rigid pipe
may be used in place of flexible hose for certain applica ­
tions. There must be a pitch of one-h·alf,)nch per foot
(i.e., a
2 - 1/2"
drop for a
5'
run) in th~~;Chaust tubing
between the engine exhaust elbow and
.th~.muffler
inlet.
Muffler may be mounted below the level of the engine if
necessary. A minimuin drop of one-foot is necessary be- .
tween the engine exhaust outlet on the hull to prevent
water from washing into the system (see Fig. 3). An in ­
crease of one standard pipe size for every ten running
feet of exhaust from the muffler to the exhaust outlet is
necessary to prevent excessive backpressure.
4. Connect the exhaust line from the upper elbow to the ex ­
haust outlet on the hull. The exhaust outlet on the hull
must be positioned so that a minimum of water will enter­
while at. anchor or under way..
Important: Be sure all fittin;s are ti;ht.
~ ~.elm.ng
on the muffler
will
damage the
h~
mterl.Or protective coating decreasing
the'life expectancy} .