FIRST:
You need
6 good cylinders! Do a Compression
Check!
You
need the TIMING / point gap-dwell
SET correctly BEFORE attempting
note:
timing must be set BELOW 800 rpm! with Vacumn Advance hose plugged!
You need
to DISCONNECT the driver's side linkage!!!
You need
2 GOOD CARBS! [ test by opening just
ONE carb at a time to see if engine runs the same for both!].
You need
TIGHT linkage..do what is necessary to stop side movement in the crossshaft and slop in any of the holes…BUT make sure linkage is not binding!
You need
the engine fully warmed up AND make
sure the CHOKES are fully opened!
[
VERTICLE!!!]
If using
a UniSyn, or other device ON TOP of the carbs....make sure the Choke plate is
not hitting the device!
You need
2 good carb bodies! If the Choke shaft hole[s] are worn...AIR
LEAK! [ apply thick grease to plug temporarily!]
If using
a "U-Tube" / Magnahelic
GAUGE...make sure you are connected to the HORIZONTAL ports! [choke pulloffs!].
If you
are using the carbs for the 1st time /
engine startup, etc., hold the choke
open, back out idle SPEED screw until throttle is totally closed......slowly
screw in until you feel / see the throttle just start to move..than 4 turns
more! Idle MIXTURE screws should
be 2 turns out from seated [ closed
fully ].
NOTE: TO BALANCE THE CARBS…..YOU ARE ADJUSTING
AIRFLOW ONLY/ IDLE SPEED SCREWS!!! NOT
THE IDLE MIXTURE SCREWS.
ONLY
AFTER GETTING THE AIRFLOW BALANCED, AND IDLE SPEED DOWN LOW [ 500-700
RPMS] DO YOU THEN ADJUST IDLE MIXTURE
SCREWS TO MAKE THE IDLE SMOOTHER!!!!
BALANCING
INSTRUCTIONS:
With
UniSyn Balancer
With
engine running on it’s own….steady RPM…..
Set
UniSyn on top of the LEFT carb. Adjust
the thumbscrew wheel [in center] to get the Ball at one of the LINES! Any line!
Preferably in the middle!
1 Without
touching anything…..set on RIGHT carb…..look at / for ball
If the
Ball is seen BELOW the LINE that the
LEFT carb was at, or doesn’t rise at all……
Turn the
RIGHT carb’s IDLE SPEED SCREW IN!! Do
this until the ball is at the same line as the LEFT carb WAS. DO NOT worry about ENGINE SPEED now!
If RIGHT carbs’ ball is ABOVE the line the LEFT
carb was at……BACK OUT RIGHT carb’s IDLE SPEED SCREW until it’s at the same line
as the LEFT carb. DO NOT worry about
ENGINE SPEED now, unless engine died.
If it died, then TURN IN the LEFT carb’s IDLE SPEED SCREW 2 turns….and
start over [ go to “1”].
WHEN
UniSyn shows EQUAL BALL position….determine if idle speed is where you want
it. DO NOT worry about rough idle NOW…..as long as it continues to run.
2 If IDLE
SPEED is too FAST…….BACK OUT BOTH carbs
IDLE SPEED SCREWS EQUALLY to get the speed you want.
RECHECK
AIRFLOW [balance] Go to “1”.
If IDLE
SPEED is too SLOW…….TURN IN BOTH carbs
IDLE SPEED SCREWS EQUALLY to get the speed you want.
RECHECK
AIRFLOW [balance] Go to “1”.
3
When
you are satisfied you may now adjust the idle MIXTURE screws to get the
smoothest idle possible!
4 When you are satisfied with idle OPEN ONE carb at a time to see that the
engine runs the same on both sides, AND that the engine returns to the same
idle speed. If not..find and fix the
binding / cause.
4
When
EVERYTHING is fine…SHUT OFF ENGINE…...WITHOUT MOVING EITHER CARB or
CROSSHAFT, carefully adjust swivel on
drivers side to just slip in the hole…..attach with clip.
5
Start
engine, and RECHECK AIRFLOW / BALANCE [ go to “1”].
Using a “U-tube
/ Water manometer”, or other GAUGE with 2 ports / “0” Center [ Magnahelic, etc.]
Look at
the NEEDLE [gauge] or the Water Levels
[ U-tube].
If the
needle is to the LEFT , Water level is
HIGHER on the left, BACK out IDLE
SPEED SCREW on LEFT carb.
If the
needle is to the RIGHT , Water level is
HIGHER on the right, BACK out IDLE
SPEED SCREW on RIGHT carb.
When
BALANCE / AIRFLOW is satisfactory
GO
TO “2” and proceed thru “5”
NOTE: depending on your air filter[s]
YOU MAY
NEED TO RE-ADJUST the IDLE
MIXTURES to obtain a smooth idle, etc!
DO NOT
adjust IDLE SPEED SCREWS!!!