ROCHESTER M & MV Single Barrel: Adjustment: Notes

If initial adjustment required to warm up engine, set idle mixture screw 3 turns out (Buick and Chevrolet, except 1969 Buick 2 turns out), 5 turns out (Oldsmobile and Pontiac), from a lightly seated position. On cars with idle stop solenoid, check solenoid position as follows:

CARBURETOR ADJUSTMENT SPECIFICATIONS

Rochester Carb. No.

Idle Speed (Engine RPM)

Float Level Setting

Metering Rod Setting

Idle Vent Setting

Fast Idle (Off Eng.)

Choke Rod Setting

Vacuum Break Setting

Unloader Setting

Auto. Choke Setting

Hot ⁽¹⁾

Fast ⁽²⁾

7028008

600

2400

9/32"

.080"

.050"

.100"

.150"

None

7028009

750

2400

9/32"

.080"

.050"

.100"

.150"

None

7028014

⁽⁴⁾

⁽⁶⁾

9/32"

.120"

.050"

.080"

.150"

.245"

.350"

⁽⁸⁾

7028015

⁽⁵⁾

⁽⁶⁾

9/32"

.130"

.050"

.100"

.150"

.275"

.350"

⁽⁸⁾

7028017

⁽⁵⁾

⁽⁶⁾

9/32"

.130"

.050"

.100"

150"

.275"

.350"

⁽⁸⁾

7028047

⁽⁵⁾

⁽⁶⁾

5/16"

.140"

.020"

.190"

.275"

.325"

⁽⁸⁾

7028057

725

750 ⁽³⁾

9/32"

.130"

.050"

.100"

.190"

.275"

.350"

⁽⁸⁾

7028065

⁽⁷⁾

2400

5/16"

.075"

.040"

.090"

.200"

.300"

.245"

⁽⁹⁾

7028067

⁽⁷⁾

2400

5/16"

.085"

.040"

.090"

.200"

.300"

.245"

⁽⁹⁾

7028075

⁽⁷⁾

2400

5/16"

.085"

.040"

.090"

.200"

.290"

.245"

⁽⁹⁾

7029008

750 ⁽¹¹⁾

2400

1/4"

.080"

.050"

.100"

.150"

⁽⁸⁾

7029014

⁽¹⁰⁾

⁽¹²⁾

1/4"

.070"

.050"

.100"

.170"

.245"

.350"

⁽⁸⁾

7029015

700

⁽¹²⁾

1/4"

.090"

.050"

.100"

.200"

.275"

.350"

⁽⁸⁾

7029017

700

⁽¹²⁾

1/4"

.090"

.050"

.100"

.200"

.275"

.350"

⁽⁸⁾

7029047

700 ⁽¹³⁾

⁽¹²⁾

9/32"

.140"

.020"

.080"

.190"

.275"

.350"

⁽⁸⁾

7029057

725

750

5/16"

.120"

.030"

.110"

.180"

.260"

.350"

⁽⁸⁾

7029165

⁽⁷⁾

2400

9/32"

.085"

.040"

.120"

.200"

.275"

.450"

⁽⁹⁾

7029166

⁽⁷⁾

2800

9/32"

.085"

.040"

.130"

.180"

.260"

.450"

⁽⁹⁾

7029167

⁽⁷⁾

2400

9/32"

.085"

.040"

.120"

.200"

.275"

.450"

⁽⁹⁾

7029168

⁽⁷⁾

2800

9/32"

.085"

.040"

.130"

.180"

.260"

.450"

⁽⁹⁾

⁽¹⁾	Auto. Trans, in Drive, Air Cond. OFF (except as noted).

⁽²⁾	Cam follower on HIGH step of fast idle cam (except as noted).

⁽³⁾	Cam follower on THIRD step, against shoulder of second step of fast idle cam.

⁽⁴⁾	Auto. Trans. Cars, set as follows:

Buick - 500 RPM in Drive (see Solenoid Note in text).
Chevrolet (Emission Control Engines) - 500 RPM with idle stop solenoid energized (see text for stopscrew adjustment). 600 RPM with Air Cond. ON.
Oldsmobile - 575 RPM with idle stop solenoid energized (see text for stopscrew adjustment).

⁽⁵⁾	Synchro-mesh Cars, set as follows:

Buick - 700 RPM (No Air Cond.) 500 RPM (with Air Cond. OFF), see solenoid note in text.
Chevrolet (Emission Control Engines) - 700 RPM with Air Cond. OFF. (If used).
Chevrolet (Non-Emission Control Engines) - 500 RPM.
Oldsmobile - 725 RPM (Air Cond. OFF) (if used).

⁽⁶⁾	All Cars, set as follows:

Buick - 20 RPM higher than hot idle speed with cam follower on LOW step of fast idle cam.
Chevrolet - 2400 RPM with cam follower on HIGH step of fast idle cam.
Oldsmobile - 750 RPM with cam follower on THIRD step of fast idle cam.

⁽⁷⁾	Special procedure required. See Text.

⁽⁸⁾	One rod diameter interference fit. See Text.

⁽⁹⁾	Rod in gauge notch on lever. See Text.

⁽¹⁰⁾	Auto. Trans. Cars, set as follows:

Buick - 500 RPM with idle stop solenoid energized (see text for stopscrew adjustment).
Chevrolet - 550 RPM with idle stop solenoid energized (see text for stopscrew adjustment).
Oldsmobile - 575 RPM with idle stop solenoid energized (see text for stopscrew adjustment).

⁽¹¹⁾	Listing is for Synchro-mesh; Auto. Trans. 600 RPM.

⁽¹²⁾	All Cars, set as follows:

Buick - 720 RPM Synchro-mesh; 620 RPM Auto. Trans, with cam follower on LOW step of cam.
Chevrolet - 2400 RPM with cam follower on HIGH step of fast idle cam.
Oldsmobile - 750 RPM with cam follower on THIRD step of fast idle cam.

⁽¹³⁾	With idle stop solenoid energized (see text for stopscrew adjustment).