[OldTee]

from. Yesterday I went to start the blue car and heard the familiar "pop" of a lean condition upon cranking. It was the second trip of the day and the engine was warm, the day was warm. The car would not start.

I went back and removed the air filter and found the pop-off valve had un-set. Put some silicon paste on the gasket, reset it and went on my way.

This car has a new style box and really does not need the pop off valve. The older box was replaced because it did not have a pop off valve.

If you have an older box I would suggest install a pop-off valve. It is not a difficult job but some care is required to seal it properly, orient it in the proper direction and make sure it is put in the correct place.

ARF

[racer]

I can't imagine a CIS 911 without a popoff valve. I missed way too many kindergarden days waiting for the flatbed to tow our then new '74 to the shop.. Mom wasn't happy either

[type954]

Also, it's important to locate the hinge of the pop-off valve in a position to insure the lid/cover doesn't foul on the airbox.

[Mark]

Same thing happened to me. I checked spark and fuel before thinking to open the airbox and check the pop-off, which had popped off. I reinstalled it using a lot more epoxy.