21 cold weather starting difficulty, Checking the carburetor, Cold weather starting difficulty -66 – JLG 601S ANSI Service Manual User Manual
Page 106: Checking the carburetor -66

SECTION 3 - CHASSIS & TURNTABLE
3-66
– JLG Lift –
3120746
c. Readjust for ambient temperature by rotating the
cover one (1) mark per 5°F from 70°F. Rotate
CCW (lean) if warmer than 70°, CW (rich) if
colder than 70°. (If actual temperature is 80°, set
at 1/32" and rotate two (2) marks CCW [lean]
direction.)
d. Tighten the three cover plate screws and check
for free rotation (no sticking or binding) of the
choke shaft.
3.21 COLD WEATHER STARTING DIFFICULTY
Machines equipped with carbureted Ford LRG-425
engines in weather conditions of 15 to 20° F (-9.5 to -6.5
C) or colder may encounter difficulty in starting.
After 10 unsuccessful attempts of starting the engine fol-
low the troubleshooting procedures below to locate the
cause of the starting difficulty.
Most Cold weather starting issues fall into the following
categories which will be addressed separately:
• Carburetor
• Ignition
• Fuel
1. Engine Receiving Fuel - After cranking the engine
for a period of time, there may be white smoke
noticed coming out of the exhaust tube. This is an
indication that the engine is in a "flooded" condition.
If the engine is flooded and will not start, follow the
procedures under Checking the Carburetor. If after
following those procedures the engine still does not
start, continue with Checking the Ignition.
2. Engine Not Receiving Fuel - If after cranking the
engine for a period of time, and there is no white
smoke coming out of the exhaust tube, follow the
procedures under Checking the Fuel.
Checking the Carburetor
After cranking the engine for a period of time there may be
white smoke noticed coming out of the exhaust tube. This
is an indication the engine is receiving fuel and is in a
“flooded” condition.
NOTE: Make sure the choke is adjusted using the asterisk
(*). There is also a zero (0) stamped on the choke.
The zero (0) is used for assembly purposes and is
not to be used as an adjustment reference.
1. Check the choke for ambient temperature setting.
The default ambient temperature setting is 70° F (21°
C), which aligns the asterisk (*) on the choke face
with the reference mark on the side of the choke
housing. The choke should be set at one notch
“clockwise” past the (*) asterisk for every 5 degrees
below 70° F (one notch “clockwise” past the (*)
asterisk for every 2.8 degrees below 21° C). This
adjustment will "richen" the fuel mixture.
2. Check if the choke “butterfly” is stuck by manually
opening and closing by hand.
3. Check the choke pull-off (butterfly stop) screw for
proper adjustment as follows:
MARK