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 | |
|---|---|---|
| 1966 Buick All Carbs | 5/8 | |
| 1967 Buick All Carbs | 1/2 | |
| 1967 Cadillac All Carbs | 7/8 | |
| 1965-66 Chevrolet All Carbs | 1 | |
| 1967 Chevrolet All Carbs | 7/8 | |
| 1966 Oldsmobile | 330" Eng. 7026254, 7036254 | 1/2 |
| 330" Eng. 7026258 | 5/8 | |
| 400" & 425" Eng. All Carbs. | 3/4 | |
| 1967 Oldsmobile | 330" Eng. All Carbs. | 5/8 |
| 400" & 425" Eng. All Carbs. | 3/4 | |
| 1966-67 Pontiac & Tempest All Carbs. | 1/2 | |
NO RELATED
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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.