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 " 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 " turn at a time. The engine
should start to smooth out. Continue to back each screw "
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" " turn out to lower the idle
speed. The Speed Screw should never be in more than 1 "
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 1" 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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