Old Buick Carburetors : BUICK MODELS 50 60 70 90 1941 1942Previous | Home | Next |
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UNLOADER ADJUSTMENT: (Figure 3) Two adjustments are necessary
to get correct unloader setting:
A. Loosen choker lever and screw assembly on shaft (H, Fig. 4). Insert .010" flat
feeler gauge between lip on fast idle cam and boss on flange casting (K, Fig.
4). Hold choke valve tightly closed and tighten choke shaft arm in place.
B. Adjust unloader lip on throttle shaft lever to give 3/16" clearance
(at N) (Gauge T109-28) between upper edge of choke valve and in-side wall of
air horn with throttle wide open.
FAST IDLE ADJUSTMENT: (Figure 4) with choke valve tightly closed, adjust fast
idle set screw (L) to give .012" clearance between throttle valve and
bore of carbureter (side opposite port) on 528S, and .015" clearance on
5335. Proceed as follows: Back out throttle adjusting screw. Then back out
fast idle set screw until it just touches the high spot of fast idle cam (M).
Then screw in fast idle set screw approximately 21/2 turns. Then adjust throttle
screw.
STARTER SWITCH ADJUSTMENT: See
Figure 3 "Car Starter Servicing Instructions"
Unloader Setting below.
IDLE ADJUSTMENT
Figure 4
Fast Idle Setting
I. The engine and choke must be warmed up before adjusting the idle mixture
or idle speed so that the choke will be wide open and the fast idle cam will
not affect the idle speed.
2. Turn idle mixture and adjusting screws in on both carbureters until closed
position can be felt with a screw driver. DO NOT FORCE SCREWS ON SEAT AS THIS
WILL DAMAGE THEM. Open each screw 3/4 ,turn.
3. Turn on ignition switch and start engine.
4. Back off both throttle adjusting screws until throttles are fully closed.
Ends of adjusting screws should then be set to barely contact boss on flange
casting when throttles are fully closed. Do not open either throttle anymore
until after mixture screws are set.
NOTE: When installing 529S and 534S, be sure that flange gasket has
5. Adjust each idle mixture screw individually to get the best setting for
that screw. The best all round engine idle will be gotten when the screws are
set toward the lean side, but not too lean to cause missing.
6. Bring up the idle speed by adjusting the throttle screw on the REAR carbureter
ONLY. The road idle speed should be maintained at approximately 9 to 10 miles
per hour in high gear or 550 r.p.m. on tachometer.
7. In the majority of cases this procedure will give a very satisfactory idle.
In a few instances it may be necessary to readjust the idle mixture screws
slightly after the engine speed has been brought up.
8. Always remember that to have a satisfactory performing car, the rear carbureter
must function on idle.
balance slot between bores. 543S and 544S use gasket without slot.
The Carter Car Starter is incorporated in the carbureter as used on Buick.
There is a milled groove on the throttle shaft into which rests a steel ball
(I). When the accelerator is depressed with the motor stopped, the ball is
forced against the plunger (2) which moves bakelite guide (3) and a contact
spring (5), shaped like the letter W, up until it makes an electrical contact
between two brass inserts molded in the bakelite terminal cap (8) and starts
the motor. The manifold vacuum acts upon the steel ball and as soon as the
foot throttle is released the ball is drawn up by suction away from the shaft,
spring returns and breaks contact, and the ball remains in the upper position
as long as the motor is in operation. Any future operation of the throttle
does not make switch contact until motor stops.
Figure 5
The W shaped contact spring (5) rests on two or more brass shims (4) with square
holes. These are very important because they determine the point at which the
switch contact is made. Contact should be made when throttle valve is opened
between 30° and 40°. if not enough of these shims are in place contact
will not be made soon enough. If there are too many of these the switch will
begin to function too soon (before 30°) and in that case there is danger
that the switch may be in contact all the time.
NOTE: Tool T109-1555 is used on 1941 and 1942 Buick carbureters. T 109-1215,
used for 1939-40 carbureters, can be brought up-to-date by
adding parts T109-156, IOc, and T109-1595, 20c.
Copyright 1941 a
CAR STARTER SERVICING INSTRUCTIONS be confused with the shims which go beneath
the contact
spring. Caution: Spring (5) and (7) must never be stretched or altered in any
way or the operation of the switch will be affected.
In making the electrical
In disassembling the switch extreme care must be taken that none of these shims
con nection
are lost and they are all returned to their proper position. It is always desir-
the red or hot
able to use Carter Car Starter Gauge TI09-1555 (Figure 7) after the switch parts
wire is always
have been reassembled, and if any new part has been installed it is absolutely
attached to
essential that it be used to make certain that the contact is not made before
30° t h e terminal
and is made before 40°. screw point-
Above the W shaped contact spring (5) will be found a cylindrical spring (7).
ing towards
Between these two there is a round washer (6) with a square hole which must not
the motor.
Figure 6
To remove the throttle shaft from carbureter it is necessary to first remove
starting switch complete. Never put oil or grease
on any switch part as it will collect d u s t a n d switch will eventually stick.
Figure 7