ROCHESTER 1MV Single Barrel: Overhaul: Carburetor

Refer to Fig 1. for disassembly and reassembly. Ensure all carburetor passages air clean. Use new gaskets on reassembly.

Fig 1: Exploded View of 1MV Carburetor

Courtesy of GENERAL MOTORS COMPANY

1975 CARBURETOR ADJUSTMENT SPECIFICATIONS

Rochester Car. No. ⁽¹⁾

Idle Speed (Engine RPM)

Float Level Setting

Metering Rod Setting

Fast Idle Choke Rod

Aux. Vacuum Break

Vacuum Break Setting

Unloader Setting

Auto. Choke Setting

Hot

Fast

Buick

5012

⁽³⁾

11/32"

.080"

.160"

.215"

.200"

.275"

⁽²⁾

5013

⁽³⁾

11/32"

.080"

.275"

.312"

.350"

.275"

⁽²⁾

5014

⁽³⁾

11/32"

.080"

.230"

.312"

.275"

⁽²⁾

Chevrolet (Exc. Vega)

5012

⁽³⁾

11/32"

.070"

.160"

.215"

.200"

.215"

⁽²⁾

5013

⁽³⁾

11/32"

.070"

.275"

.312"

.350"

.275"

⁽²⁾

5014

⁽³⁾

11/32"

.070"

.230"

.312"

.275"

⁽²⁾

Chevrolet Vega

5024

550/750

2200

1/8"

.....

.080"

.450"

.100"

.375"

.....

5025

700

2000

1/8"

.....

.080"

.450"

.100"

.375"

.....

5028

550/750

2200

1/8"

.....

.080"

.450"

.100"

.375"

.....

5029

700

2000

1/8"

.....

.080"

.450"

.100"

.375"

.....

Oldsmobile

5012

425/550

⁽³⁾

11/32"

.080"

.160"

.215"

.200"

.275"

⁽²⁾

5013

425/850

⁽³⁾

11/32"

.080"

.275"

.312"

.350"

.275"

⁽²⁾

5014

425/550

⁽³⁾

11/32"

.080"

.160"

.215"

.200"

.275"

⁽²⁾

Pontiac (Exc. Astre)

5012

⁽³⁾

11/32"

.080"

.160"

.215"

.200"

.275"

⁽²⁾

5013

⁽³⁾

11/32"

.080"

.275"

.312"

.350"

.275"

⁽²⁾

5014

⁽³⁾

11/32"

.080"

.230"

.312"

.275"

⁽²⁾

Pontiac Astre

Man Trans.

700

2000

1/8"

.....

.080"

.....

.130"

.375"

.....

Auto Trans.

750

2200

1/8"

.....

.080"

.....

.130"

.375"

.....

⁽¹⁾	Prefix number is 704

⁽²⁾	One Rod Diameter Lean.

⁽³⁾	Refer to Emission Control Tune-Up Decal.

1976 CARBURETOR ADJUSTMENT SPECIFICATIONS

Rochester Car. No ⁽¹⁾.

Idle Speed (Engine RPM)

Float Level Setting

Metering Rod Setting

Fast Idle Choke Rod

Aux. Vacuum Break

Vacuum Break Setting

Unloader Setting

Auto. Choke Setting

Hot ⁽²⁾

Fast

Chevrolet

6012

425/550

2100

11/32"

.084"

.090"

.215"

.110"

.265"

⁽³⁾

6013

425/850

2100

11/32"

.082"

.090"

.215"

.110"

.265"

⁽³⁾

6014

425/550

2100

11/32"

.080"

.090"

.215"

.110"

.265"

⁽³⁾

6015

425/850

2100

11/32"

.080"

.090"

.215"

.110"

.265"

⁽³⁾

6016

425/600

2200

11/32"

.080"

.115"

W.O.

.140"

.265"

⁽³⁾

6018

425/550

2100

11/32"

.084"

.090"

.215"

.110"

.265"

⁽³⁾

6022

550/750

2200

1/8"

.....

.045"

.450"

.060"

.215"

⁽³⁾

6023

750/1200

1500

1/8"

.....

.045"

.450"

.060"

.215"

⁽³⁾

6026

550/750

2200

1/8"

.....

.045"

.450"

.060"

.215"

⁽³⁾

6027

750/1200

2200

1/8"

.....

.045"

.450"

.060"

.215"

⁽³⁾

6314

425/600

1700

11/32"

.083"

.135"

.275"

.150"

.265"

⁽³⁾

Oldsmobile

6012

425/550

⁽⁴⁾

11/32"

.080"

.100"

.265"

.140"

.265"

⁽³⁾

6013

425/850

⁽⁴⁾

11/32"

.080"

.140"

.320"

.165"

.265"

⁽³⁾

6014

425/550

⁽⁴⁾

11/32"

.080"

.100"

.265"

.140"

.265"

⁽³⁾

6015

425/850

⁽⁴⁾

11/32"

.080"

.140"

.320"

.165"

.265"

⁽³⁾

6018

425/550

⁽⁴⁾

11/32"

.080"

.100"

.260"

.140"

.265"

⁽³⁾

6314

425/550

⁽⁴⁾

11/32"

.080"

.135"

.320"

.165"

.265"

⁽³⁾

Pontiac

6012

550

⁽⁴⁾

11/32"

.....

.090"

.215"

.110"

.265"

⁽³⁾

6013

850

⁽⁴⁾

11/32"

.....

.090"

.215"

.110"

.265"

⁽³⁾

6014

550

⁽⁴⁾

11/32"

.....

.090"

.215"

.110"

.265"

⁽³⁾

6015

850

⁽⁴⁾

11/32"

.....

.090"

.215"

.110"

.265"

⁽³⁾

6018

⁽⁵⁾550

⁽⁴⁾

11/32"

.....

.090"

.215"

.110"

.265"

⁽³⁾

6022

750

⁽⁴⁾

1/8"

.....

.045"

.450"

.060"

.215"

⁽³⁾

6023

700

⁽⁴⁾

1/8"

.....

.045"

.450"

.060"

.215"

⁽³⁾

6026

750

⁽⁴⁾

1/8"

.....

.045"

.450"

.060"

.215"

⁽³⁾

6027

700

⁽⁴⁾

1/8"

.....

.045"

.450"

.055"

.215"

⁽³⁾

6312

600

⁽⁴⁾

11/32"

.....

.135"

.275"

.150"

.265"

⁽³⁾

6314

600

⁽⁴⁾

11/32"

.....

.135"

.275"

.150"

.265"

⁽³⁾

⁽¹⁾	Prefix number is 1705.

⁽²⁾	First figure shown is solenoid de-energized.

⁽³⁾	Refer to "CHOKE COIL ROD ADJUSTMENT ".

⁽⁴⁾	Refer to Emission Control Tune-Up Decal.

⁽⁵⁾	LeMans with Air Cond. is 575.