JLG 450AJ ANSI Service Manual - Manual (Page 90)

SECTION 2 - PROCEDURES
2-72 – JLG Lift – 3120749
2.29 AUTOMATIC CHOKE ADJUSTMENT -
FORD ENGINE
1. At 70°F the choke plate should be open 1/32" (not
touching the choke bore).
2. If the ambient temperature is not 70°F, an additional
adjustment is required.
a. Loosen the three cover plate screws.
b. Adjust the cover to open the choke plate 1/32".
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.
2.30 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.
1/32"
MARK