Section 6 − Operating Welding Generator; Engine Controls; Cold Weather Engine Operation - Miller TRAILBLAZER 302 AIR PAK Owner's Manual

SECTION 6 − OPERATING WELDING GENERATOR

6-1. Engine Controls

1 Engine Control Switch
Use switch to start engine, select speed,
and stop engine. In Run position, engine
runs at weld/power speed. In Auto/Speed
position, engine speed responds to the
work activity and load:
S
Idle
S
Compressor
S
Small Stick/TIG Welding
Loads Up To 165 A
S
Compressor
S
MIG/Heavy Stick Welding
Loads
S
Compressor
S
Generator Power

6-2. Cold Weather Engine Operation

1 Engine Control Switch Position For
Infrequently Loaded Unit
2 Engine Control Switch Position For
Frequently Loaded Unit
Carburetor Icing
Carburetor icing causes the unit to drop be-
low the normal idle speed and then stall.
This condition occurs when the tempera-
ture is near freezing and the relative humid-
ity is high. Ice forms on the throttle plate and
inner bore of the carburetor. The engine
typically restarts without problems but soon
stalls again.
S Treat gasoline with a fuel de−icer prod-
uct (isopropyl alcohol).
S Place the Engine Control switch in the
Run position.
S Run engine only when expecting to fre-
quently load it.
OM-229 930 Page 30
To view engine speed: with engine running
and Process Selector switch in any Stick
Hot position, cycle switch from Auto Speed
to Run three times. Meters will display en-
gine speed ± 16 RPMs. Turn machine off to
reset display.
Use switch to reset engine and compressor
2400 RPM
oil change hours. See section 7-1.
2400 RPM
.
The unit will not return to idle speed
3000 RPM
when the remote contactor is on and
3000 RPM
Process/Contactor switch is in any
Wire position. The unit will return to idle
3600 RPM
speed in all other modes.
3600 RPM
3600 RPM
Breather Icing
Oil breather/pulse line icing occurs in se-
vere cold (continuously below 0_F). Mois-
ture accumulates in the oil from piston ring
blow−by if the engine is extensively idled.
This may cause vacuum line freezing, oil
breather tube freezing or ice in the carbure-
tor. All of these cause operating problems.
Due to ice in the lines, the engine may not
restart until it is warmed to above freezing.
S Load engine and reduce idle times to
prevent engine shutdowns.
S Use an electric fuel pump to avoid
pulse line freezing.
S Install engine cold−weather kit.
Kohler (1-800-544-2444) offers kit for cold
weather operation. The user can install kit.
Kit pulls heated air from the muffler surface
1
2
1
Ref. 804 857-B / Ref. 229 219-C
2 Engine Choke Control
Use control to change engine air-fuel mix
when starting engine.
To Start: Pull out choke and turn Engine
Control switch to Start position. Release
switch and slowly push choke in when
engine starts.
.
If the engine does not start, let the
engine come to a complete stop before
attempting restart.
.
During cold weather some gasoline en-
gines encounter difficulties that are
easily remedied. See Section 6-2 and
11-4.
To Stop: Turn Engine Control switch to Off
position.
2
Ref. 229 219-A
into the carburetor and shuts the cold air off.
This increases engine temperature during
operation in both idle and high speed.
.
When the ambient temperatures be-
come warmer (above 45_F) the air flow
will have to be returned to normal.
Synthetic Oil
For temperatures below zero, synthetic oil
improves engine starting. After the 50 hour
break−in period, the engine oil can be
switched between synthetic and non-syn-
thetic type oils.
.
Do not extend the 100 hour recom-
mended oil change interval.
In severe cold, use synthetic grades 5W20
or 5W30. See engine maintenance label for
additional information.