Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Secondary Air Valve Spring Wind-up
If adjustment required, use 1/16" Allen wrench to loosen lockscrew, turn adjusting screw counterclockwise until all spring tension removed. Hold air valve closed and turn adjusting screw clockwise until torsion spring just contacts pin in shaft, then wind-up spring by continuing to turn adjusting screw clockwise the exact amount shown in table below. Hold adjusting screw in this position and tighten lockscrew securely.
| Car Model | Adjusting Screw Turns | |
|---|---|---|
| Buick | 1/2 | |
| Cadillac | (I968) | 1/2 |
| (7029230, 31 Carbs.) | 1/2 | |
| (7029232, 33 Carbs.) | 7/16 | |
| Chevrolet | (7028207, 8, 12, 13 Carbs.) | 3/8 |
| (7028209, 10, 11, 16, 17, 18, 19, 29 Carbs.) | .7/8 | |
| (Except 7029202, 03 Carbs.) | 13/16 | |
| (7029202, 03 Carbs.) | 7/16 | |
| Oldsmobile | (1968 350" Engine Carbs.) | 1/2 |
| (1968 400" & 450" Engine Carbs.) | 3/4 | |
| (1969 except 7029250 Carb.) | 3/4 | |
| (7029250 Carb.) | 1/2 | |
| Pontiac, Tempest & Firebird | 1/2 | |
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.