Solving Carb Problems

Many Scouts are equipped with the 350 c.f.m Holley
Carb. From about 76 and up the carbs had internal
accelerator pumps.

Often Scouts have the problem of off idle hesitation,
or a stumble while accelerating.  Some people attribute
this problem to an incorrectly adjusted choke.  Although
it may be the case it has been my experience that the 
accelertor pump is the culprit.  Due to old age, the rubber diaphram
often becomes stiff or shrinks. The bad diaphram
causes a lean stumble.  Rebuilding your old carb
is much more easy than you think.  If your truck has an older
2bbl or an aftermarket carb with an external accelerator pump
the acc. pump diaphram can be changed without rebuilding the 
carb.  Pump actuating cams can be purchased for these carbs
to tune or time the fuel squirt.


The Holley 500  2bbl is a great carb for those who would like more
power from their 304 or 345.  The 500 flows 150 cfm more than 
than stock and some years almost doubling the accelerator
pump. The 500 comes with #72 jets. The stock carbs come 
with about 53 or 54s. The 73s are much too large for the 
IH motors.  I  recommend that you start around a #63 jets
and play around with your jetting to achive optimum results.


 IH engines only came with two types of 4bbl intakes.Both fit
the 345 and 392 only. Scouts came equipped with a spread 
bore manifold with a Carter Thermoquad.Some Travelalls came
with a square bore manifold below a Holley carb. I have found 
the Thermoquad to be less than reliable.Mostly made of plastic 
the 20 year old carb becomes hard and brittle causing fuel leaks 
and poor fuel distribution.The rodchester Q-jet has been prove
to be a great carb.Found on most older Chevrolet v8s the Q-jet 
is a direct bolt on replacement.The Q-jet(spread bore)
has two different types of fuel inlets one from the side and one
from the front.The front fuel inlet will not clear the thermostat 
housing. Once you find the correct carb it is just a matter of
bolting it on and setting the fuel air mixture.. You may need to
 adjust the throttle cable for maximum performance.

Edlebrock makes the Performer carberator.An all  cast 
 aluminium bodied mixer is a great carb.
The Performer is a square bore carb and needs a  adapter to
be used on a stock spread bore manifold.Edlebrock and Mr
Gasket make good adapters.The Edlebrock adapter is a
four hole spacer and more suited for bottom end power.If you
are using a adapter you will need a low profile air cleaner to
fit under the hood. If you have a body lift a regular air cleaner
may work.

Remember  a carb is only as good as you maintain it.Change
the fuel filter at regular intervals and keep the internals clean
with a good carb cleaner.