PS Magazine - TB 43-PS-576
PS, The Preventative Maintenance Monthly
ISSUE 576
NOVEMBER 2000
M157 Smoke Generator . . .
After setting the PREHEAT, hold the
FUEL switch in START until the FUEL
indicator comes on. Release the FUEL
switch and let it flip to RUN.
After the AIR indicator lights and
the PREHEAT indicator goes off, hold
the ENGINE switch in START for 1 to
2 seconds and then release it. Wait 3
seconds.
Hold the ENGINE switch in START
until the ENGINE indicator lights and
the SMOKE TEMP indicator reaches
the green band. Release the ENGINE
switch and let it flip to RUN.
Wait until the engine temperature
reaches 800
o
F. Hold the FOG OIL
switch in START until the FOG OIL
indicator lights, then let the switch flip
to RUN. You’re ready to smoke.
For more information, see Pages
2-29 through 2-34 in TM 3-1040-
283-10.
The fuel folks also need to add 16
ounces of DGME icing inhibitor, NSN
6850-01-377-5075, to every 40 gallons
of fog oil.
For the engines, use Type 2 automo-
tive combat gasoline (MOGAS), NSN
9130-00-240-8201, in below-freezing
weather,
or
mix 16 ounces of isopro-
pyl alcohol, NSN 6810-00-286-5435,
to each 5 gallons of untreated gaso-
line. Keep all fuel tanks as full as pos-
sible to prevent condensation.
If you don’t have Type 2 gas, use
engine primer fuel, NSN 6850-00-823-
7861, to start the M157 in cold weather.
Spray the primer into the nozzle as-
sembly for 2 to 3 seconds and step
away (primer fuel is very flammable).
Have a buddy immediately push the
Operating
Percentage of
Temperature
Fog Oil to
Diesel/Kerosene
Above 32
o
F1
0
0
/
0
32
o
to –10
o
F7
5
/
2
5
–11
o
to –25
o
F6
0
/
4
0
–26
o
to –40
o
F5
0
/
5
0
ENGINE switch to START. Don’t hold
it in START longer than 15 seconds or
you’ll lose too much air pressure to
start. Do this procedure up to three
times more. If the M157 still won’t
start, tell your repairman.
For the M157A2, smoking in the cold
is a little different. You mix fog oil just
like you did for the M157, and add 16
ounces of isopropyl alcohol to each 5
gallons of untreated gasoline or 2
ounces of icing inhibitor to each 5 gal-
lons of other untreated fuel. Then use
these preheat cycles according to the
fuel you’re using:
Fuel
Preheat Cycle
MOGAS
0
JP-1
1
JP-4
1
JP-5 turbine
3
JP-8 turbine
4
Diesel fuel-arctic
4
DF-1 diesel
4
Spray primer fuel in nozzle assembly
i'm
so cold
i don't think i'll
be able to smoke
today.
don't
worry, i've got
us
covered
.
45
NOV 00
n cold weather, condensation in the
M157’s fog oil tank can freeze and
block the fog oil pump strainers. That
stops smoking cold. But there are ways
to smoke cold problems.
When it’s below freezing, have your
fuel supply folks add kerosene or
diesel fuel to the fog oil to form a
mixture that flows easier. The table
below shows the right mix of fog oil
and fuel.
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