1bbl icing up
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
There is a hot-air duct system to prevent this. The air cleaner snorkel has a vacuum motor that opens and closes a door so that the carburetor only takes in warm air wafted from the exhaust manifold on startup. As the underhood temperature increases, a bimetallic vacuum switch on the air cleaner switches off the signal and lets the carburetor draw in fresh air from outside. Over time these parts wear out or are removed, but the factory setup is intended to prevent this situation.
