Choke Unloader

Open throttle valve wide open. Apply light closing pressure to choke valve. Measure specified clearance between lower edge of choke valve and air horn wall. See Figure.
Measurement can be made with a specified drill or pin gauge. To adjust, bend choke unloader tang.

1976 CARBURETOR ADJUSTMENT SPECIFICATIONS

Rochester Car. No.

Idle Speed (Engine RPM)

Float Level Setting

Metering Rod Setting

Fast Idle (Off Engine)

Choke Rod Setting

Vacuum Break Setting

Unloader Setting

Auto. Choke Setting ⁽²⁾

Hot ⁽¹⁾

Fast

17056030

⁽¹⁾

5/32"

.072"

N/A

.065"

.085"

.200"

3 Rich

17056031

⁽¹⁾

5/32"

.072"

N/A

.065"

.085"

.200"

3 Rich

17056032

⁽¹⁾

5/32"

.073"

N/A

.065"

.085"

.200"

3 Rich

17056034

⁽¹⁾

5/32"

.073"

N/A

.065"

.085"

.200"

3 Rich

17056035

⁽¹⁾

5/32"

.073"

N/A

.065"

.085"

.200"

3 Rich

17056036

⁽¹⁾

5/32"

.072"

N/A

.065"

.085"

.200"

3 Rich

17056330

⁽¹⁾

5/32"

.072"

N/A

.065"

.085"

.200"

3 Rich

17056331

⁽¹⁾

5/32"

.072"

N/A

.065"

.085"

.200"

3 Rich

17056332

⁽¹⁾

5/32"

.073"

N/A

.065"

.085"

.200"

3 Rich

17056334

⁽¹⁾

5/32"

.073"

N/A

.065"

.085"

.200"

3 Rich

17056335

⁽¹⁾

5/32"

.073"

N/A

.065"

.085"

.200"

3 Rich

⁽¹⁾	See Emission Control Tune-Up Decal.

⁽²⁾	Number of notches, rich or lean.

1977 CARBURETOR ADJUSTMENT SPECIFICATIONS

Rochester Car. No.

Idle Speed (Engine RPM)

Float Level Setting

Metering Rod Setting

Fast Idle (Off Engine)

Choke Rod Setting

Vacuum Break Setting

Unloader Setting

Auto.⁽²⁾ Choke Setting

Hot

Fast

17057013

⁽¹⁾

2000

3/8"

.070"

.100"

.120"

.125"

.325"

1 NR

17057014

⁽¹⁾

2000

3/8"

.070"

.085"

120"

.120"

.325"

2 NR

17057015

⁽¹⁾

2000

3/8"

.070"

.100"

120"

.125"

.325"

1 NR

17057016

⁽¹⁾

2000

3/8"

.070"

.095"

120"

.125"

.325"

1NL

17057018

⁽¹⁾

2000

3/8"

.070"

.095"

120"

.125"

.325"

1 NR

17057020

⁽¹⁾

2000

3/8"

.070"

.085"

120"

.120"

.325"

2 NR

17057030

⁽¹⁾

2400

5/32"

.080"

.050"

120"

.080"

.200"

3 NR

17057031

⁽¹⁾

2300

5/32"

.080"

.050"

120"

.080"

.200"

3 NR

17057032

⁽¹⁾

2400

5/32"

.080"

.050"

120"

.080"

.200"

3 NR

17057034

⁽¹⁾

2400

5/32"

.080"

.050"

120"

.080"

.200"

3 NR

17057035

⁽¹⁾

2300

5/32"

.080"

.050"

120"

.080"

.200"

3 NR

17057042

⁽¹⁾

2400

5/32"

.080"

.050"

120"

.080"

.200"

2 NR

17057044

⁽¹⁾

2400

5/32"

.080"

.050"

120"

.080"

.200"

2 NR

17057045

⁽¹⁾

N/A

5/32"

.080"

.050"

120"

.080"

.200"

2 NR

17057310

⁽¹⁾

1800

3/8"

.070"

.....

120"

.....

INDEX

17057312

⁽¹⁾

1800

3/8"

.070"

.....

120"

.....

INDEX

17057314

⁽¹⁾

1800

3/8"

.070"

.100"

120"

.110"

.225"

INDEX

17057318

⁽¹⁾

1800

3/8"

.070"

.100"

120"

.110"

.225"

INDEX

17057332

⁽¹⁾

N/A

5/32"

.080"

.050"

120"

.080"

.200"

2 NR

17057334

⁽¹⁾

N/A

5/32"

.080"

.050"

120"

.080"

.200"

2 NR

17057335

⁽¹⁾

N/A

5/32"

.080"

.050"

120"

.080"

.200"

2 NR

⁽¹⁾	See Emission Control Tune-Up Decal.

⁽²⁾	Number of notches rich or lean.

1978 CARBURETOR ADJUSTMENT SPECIFICATIONS

Rochester Carb. No.

Idle Speed (Engine RPM)

Float Level Setting

Metering Rod Setting

Choke Lever Setting

Choke Rod Setting

Vacuum Break Setting

Unloader Setting

Auto. Choke Setting

Hot

Fast

Chevette

17058031

⁽¹⁾

2400

5/32"

.080"

.120"

.105"

.150"

.500"

2 NR

17058032

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"

.500"

3 NR

17058033

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"

.500"

2 NR

17058034

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"

.500"

3 NR

17058035

⁽¹⁾

2300

5/32"

.080"

.120"

.080"

.130"

.500"

3 NR

17058036

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"

.500"

3 NR

17058037

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"

.500"

2 NR

17058038

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"

.500"

3 NR

17058042

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"⁽³⁾

.500"

2 NR

17058044

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"⁽³⁾

.500"

2 NR

17058045

⁽¹⁾

2300⁽²⁾

5/32"

.080"

.120"

.080"

.130"⁽³⁾

.500"

2 NR

17058332

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"⁽³⁾

.500"

2 NR

17058334

⁽¹⁾

2400

5/32"

.080"

.120"

.080"

.130"⁽³⁾

.500"

2 NR

17058335

⁽¹⁾

2300⁽²⁾

5/32"

.080"

.120"

.080"

.130"⁽³⁾

.500"

2 NR

Chevrolet Camaro Nova

17058013

⁽¹⁾

2000⁽⁴⁾

3/8"

.080"

.120"

.180"

.200"

.500"

INDEX

17058014

⁽¹⁾

2100⁽⁴⁾

5/16"

.100"

.120"

.180"

.200"

.500"

INDEX

17058020

⁽¹⁾

2100⁽⁴⁾

5/16"

.100"

.120"

.180"

.200"

.500"

INDEX

17058314

⁽¹⁾

2000⁽⁴⁾

3/8"

.100"

.120"

.190"

.245"

.400"

INDEX

⁽¹⁾	See Emission Control Tune-Up Decal.

⁽²⁾	Not adjustable.

⁽³⁾	Above 30, 000 miles, set to 0.160".

⁽⁴⁾	Transmission in NEUTRAL.

1979 CARBURETOR ADJUSTMENT SPECIFICATIONS

Application	Float Level Setting	Metering Rod Setting	Choke Coil Lever Setting	Auto. Choke Setting	Choke Coil Rod Setting	Vacuum Break Setting	Choke Unloader Setting
17059013	3/8"	.095"	.120"	Index	.180"	.200"	.400"
17059014	3/8"	.095"	.120"	Index	.180"	.200"	.400"
17059020	3/8"	.095"	.120"	Index	.180"	.200"	.400"
17059314	3/8"	.100"	.120"	Index	.190"	.245"	.400"