Holley MCarbHoll2110 1957 Carburetor manual
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Road check the vehicle, if possible, before
making any adjustments on the carburetor to im
prove performance. Dragging brakes, poor wheel
alignment, low tire pressure, and other causes of
undue friction tend to retard engine performance.
Evidence of leakage or dents in the exhaust system
can cause trouble. Check the color of the exhaust
for indications of an over-rich mixture, for ex
cessive oil consumption and compression loss.
A rough running engine coupled with a strong odor
of gasoline may resultfrom aflooding carburetor.
Improper engine temperature should be corrected.
Many faults may be detected by a visual inspection
of the engine in operation. Remedy loose or dis
connected wiring, leaking fuel and water con
nections, possible short circuits, and other faults.
made of the fuel pump pressure.
Excessive fuel
pump pressure causes engine to flood resulting
in poor fuel economy. Low pump pressure is as
sociated with a lean mixture and poor performance.
Make a preliminary inspection of the carbu
retor after first removing the air cleaner. Check
the position of the choke plate with the engine run
ning. Throttle the engine down to idle, then com
pletely close both idle adjusting needles. If the
engine continues to run for even a short interval
after this is done, it usually indicates one or two
faults. The tips or seats of the idle adjusting
needles may be damaged, or idle speed set too
high, or else there are deposits of carbon in the
throttle bores near the throttle plates.
After a check has been made of the vehicle,
examine the engine. Check or set the following
in accordance with manufacturer's specifications:
distributor breaker points, spark plug gap, igni
tion timing, condenser capacity, valve settings,
intake manifold for leaks, compression, gaskets,
carburetor body and flange screws, and inlet fuel
The fuel system should also be inspected.
Examine all fuel lines for collasped sections and
other damage. Make a manual check of fuel line
connections for looseness or leakage.
Check the
fuel tank vent for possible obstructions.
Even a
partially-clogged vent may cause the engine to
cut out after a f ew minutes of high- speed operation.
Clean the fuel pump sediment chamber and the fuel
filter, if there is one. Using a vacuum gage, check
the fuel pump for air leaks. Connect the gage to
the line leading to the pump.
A vacuum reading
less than normal at the idle indicates an air leak
or a faulty fuel pump. A careful check should be
To continue with the carburetor inspection,
stop the engine and check the tightness of the
carburetor to manifold, and manifold to engine
connections. Inspect all carburetor connections
and linkages. Examine the accelerating pump link
to insure that it is correctly positioned.
If by now the trouble has not been located, re
move the carburetor from the engine and dis
assemble. Thoroughly clean and inspect each part,
using the procedure laid down in the Service
Manual. The accompanying troubleshooting chart
lists specific carburetor complaints and discusses
the various parts which may be at fault. A rigor
ous cleaning and inspection, coupled with the re
placement of faulty parts and care in reassembly,
should prevent recurrence of the complaint.
Many performance complaints attributed to
the carburetor may be the result of poor
driving habits, topography and/or weather
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