The Stovebolt Site Forums The Shop Area Engine Shop choke question

Just had the carburetor off so I could replace a cracked exhaust manifold. It's been a long time since I've messed with the choke but when I put it back together I noticed that the engine stalls when you pull the choke all the way out. With the cable pulled out, the valve is completely closed. Is it supposed to be that way or is that what's causing the stalling? With the choke pulled out, should the valve be open just a little, as in, not quite closed all the way? Seems to make sense that if it's shut completely the engine can't breathe but thought I'd ask anyway.

Yes. If the choke is pulled out the engine will stall. You only use a choke on a cold engine start. When the engine starts push the choke about halfway in. Some carbs do have a spring on the butterfly that lets the air pull it partway open when it starts. Then push it all the way in after a little warmup. Do not use a choke more then necessary to keep the engine from hesitation. Over choking washes oil off the cyl walls. & polutes the oil. It causes carbon buildup in the engine & can foul up the spark plugs.
George

This is where Jerry's (Hot Rod Lincoln) comment (in a different thread) about automatic chokes being smarter than drivers originates.

If the choke plate is completely closed, the engine will stall UNLESS many carburetor engineers knew that the end customer would pull the choke clear through the firewall if possible; so they designed a choke valve with a relief valve that was spring-loaded. With this system, even if the choke valve were completely closed, the relief valve would open and prevent the engine from stalling.

Edit: George types faster than I.

Jon.