Carburetor Set Up and Adjustment34 ICT |
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Base
line Settings Speed Screw 1 to 11/2 turns Mixture Screw 2 turns Your settings with engine running Speed Screw______________ Mixture Screw______________ |
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It
is most important to verify all linkage and levers are installed without
binding and the linkage opens to full throttle position and is allowed to
close to the Idle Speed Screw. This is the number one and two reasons
for tuning errors, improper linkage installations and over tightened
linkage nut, causing binding in the linkage assembly. CALIBRATIONS MAY VARY DUE TO REGIONAL FUELS AND STATE OF ENGINE TUNE AND PERFORMANCE. POOR RUNNING QUALITY DOES NOT MEAN YOU HAVE A CARBURETION PROBLEM. THE ADVANTAGE OF THE WEBER CARBURETOR IS ITS EASE OF ADJUSTMENT AND TUNING. “LEAN BEST IDLE” Procedures After confirming the linkage allows the throttle to seat against the Idle Speed Screw. Back off the Idle Speed Screw until it doesn’t touch the throttle lever. Turn the Speed Screw in until it contacts the throttle lever and turn it in 1 ½ turns. Repeat this with the other carburetor. Turn the Mixture Screw in until it “LIGHTLY” seats, then back out the screw 2 full turns. a.
Start the engine, it will run slow and like a tractor. As long as
it will stay running, the idle speed is not important at this point. b.
First, turn in each mixture screw until the engine runs worse, then
back out the screw ¼ turn at a time. The engine should start to smooth
out. Continue to back each screw ¼ turn at a time until the screw does
nothing or runs worse. Then turn it back in to the point where it ran
best. You want to tune the engine by sound. Adjust each mixture screw to
the best, fastest and smoothest running point. Do this procedure with each
mixture screw. c.
Now you may adjust the Idle Speed Screw. It should be sensitive and
only “require” ½ turn out to lower the idle speed. The Speed Screw
should never be in more than 1 ½ turns in. d.
These carbs are commonly used in pairs, this makes the
synchronization important, be sure to bring the high flowing carb down to
the low flow carb. Then bring them both up to “proper” Idle speed. The
Idle Speed Screws are never opened more than 1½ turn in maximum. e.
After synchronizing multiple carbs, reconfirm steps b. c. & d. Pump
By-pass Valve: The
pump by-pass valve is designed to allow fuel into the pump circuit and
when depressed, by-pass a
percentage of the fuel delivered to the accelerator pump nozzle/jets.
(by-pass through a hole on the side of the valve back into the fuel bowl).
We have included the zero by-pass valve. (no hole in the side) This will
deliver all of the available fuel to the engine and not by-pass back into
the fuel bowl. This will increase the duration and fuel volume of the pump
shot with the original pump nozzle/jets. The accelerator pump by-pass
valve is located in the bottom of the fuel bowl. One is required per
carburetor.
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Simple
Rules for low speed calibration If the mixture screw is more than 21/2
turns out turns then the Idle jet is too lean (too Small). When the
mixture screw is less than 11/2 then
the Idle jet is too rich (too large). These assumptions are based on the
fact that the speed screw setting is not opened more than 11/2 turns. If
the speed screw has to be opened 2 or more turns then this is also an
indication of a lean condition usually requiring greater change. At times
it may appear to be showing signs of richness or flooding it is really a
lean condition. See pictures and notes in the tech 2 article supplied in
the kit instructions, view and please understand the need to keep throttle
plate as near to closed as possible so as not to prematurely expose the
transition holes. This is what causes the visible rich condition, and
confirms the need to increase the jet size. JET KITS are available if
needed. EXAMPLE With
the speed screw set at no more than one half (1 1/2) turns in after contact with
the stop lever; and the best idle occurring with the mixture screw
set at 3 turns from bottom,
indicates the need for a larger Idle jet. Achieving the best idle at under
2 turns indicates the need for a smaller idle jet. The secret to
understanding the critical nature of the carburetor set up and the
advantages of a WEBER over other carburetors is the Idle circuit. Referred
to as the low speed circuit by Weber, this circuit is responsible for 80%
of the driving operation. This is the reason that the Weber should give a
fuel economy improvement over most factory carbs along with significant
performance gains. In the worst case you should not see a
significant fuel economy loss over stock, while improving HP &
Drivability. The Weber Carburetor is a sequentially timed device to the
motor like the distributor. Time taken in the setup will provide more fun
later. If you should need to call REDLINE for technical
assistance we will need to know your final settings to help. Technical
assistance is free for the first 60 days of purchase. Units in service
over 60 days may be assessed a service fee. All charges will be noted up
front after a brief consultation to determine any possible defect. If the
carb is out of the warranty period and no defect is determined we will
estimate the possible cost of tech support or recommend literature
available that may help.
ALL WARRANTIES
ARE HANDLED DIRECTLY THROUGH REDLINE
NOT THE RETAILER. DO NOT SEND PARTS TO MANUFACTURER WITHOUT CALLING FOR
TUNING CONSULTATION AND WARRANTY CONFIRMATION OR INSPECTION RETURN
AUTHORIZATION. PARTS RETURNED WITHOUT AUTHORIZATION NUMBERS
WILL BE REFUSED AND RETURNED FREIGHT COLLECT.
PARTS
RETURNED FOR INSPECTION AND WARRANTY CONSIDERATION AND NOT FOUND TO BE
DEFECTIVE WILL BE CHARGED A MINIMUM INSPECTION AND ADJUSTMENT CHARGE OF
$35.00 AND RETURNED FREIGHT COLLECT. Contact REDLINE at 1 800 733 2277 ex 7457 Monday thru
Friday 8:00 to 5:00 Pacific Standard Time
Non warranty Tech support is on a
fee for services basis with minimum charge
of 35.00 per problem resolution
. With tech support calibration and tuning parts will be available
at discount pricing as
well as access to technical support documents and mailings |
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