Is there such a thing as testing for a lean or rich carburetor by restricting air?

Answer by  Amber40 (24961)

I have never heard of this technique and can't imagine how it would help. If anything it would cause an false rich condition. A pyrometer or other gas measuring device should be used to read the exhaust.

Answer by  leroy (231)

No such thing as that. Restricting the the air will make it burn rich. You would need to check for rich/lean condition at the exhaust, ideally with a tester that can read the oxygen levels of the exhaust. The desired level is 14. 7, higher than that is lean, lower is rich.

Answer by  spliffy (56)

Restricting the airflow into a carburetor will alter the air fuel mixture and thus can be an aid indetermining how rich or lean the mix produced by the carburetor is, but altering the rate at which fuel is added to the mix is a better way to determine this. This will yield a more accurate result.

Answer by  tmoney (176)

Yes, there is such a thing. If the air is restricted, and the carb can't compensate by reducing fuel flow, it will run rich. If it cuts fuel flow too much, the car will run lean.