Carburetor question
 

What is it about the float level that creates the problem where a vehicle will stall when coming to a stop, then starts back easily and runs fine. We have a 30 sport coupe right now that runs and starts and idles great, but stalls coming to a stop.

Re: Carburetor question
 

Common model a fault. The float pivots front to back,shutting off the needle valve when stopping. That's why it was changed to side to side on the Model B

Re: Carburetor question
 

Use the hand throttle to rev up as you come to a stop. Idle down once you are stationary.

Re: Carburetor question
 

This is caused by your float level being wrong. Set it correctly and all will be well. Les Andrews' book gives simple directions.

Re: Carburetor question
 

If all is adjusted correctly the stall will only happen on panic or very hard stops. I think the cause is too much gas to the jet in the bowl. I think shutting the float valve would not stall the car unless it was shut for quite a long interval or the fuel was Very low in the bowl

Re: Carburetor question
 

I have driving my Model A 35 years with a Zenith carb and do not experience the stalling on a hard stop. I believe having the correct float level is the reason for this.

Re: Carburetor question
 

Franklin, I have thought the same thing. The float closes the gas flow to the bowl, and I cannot believe you will use up all the gas in the bowl while decelerating to a stop.

Re: Carburetor question
 

MY 30 P/U has a rebuilt carb. Has run great for six months. This past weekend it started to stall at stop signs. Do I have the same problem with float heigth?
Was running great!!

Re: Carburetor question
 

Try adjusting it down a little and see what happens.

Re: Carburetor question
 

The secondary well might be plugged. Would not hurt to pull the carb apart (Zenith) And check the idle circuit.

Re: Carburetor question
 

If the car was fine before I would lean toward the secondary well too.The float level doesn't change with use,unless something goes bad.If the little holes to feed the well get plugged when you stop fast the well empties and can't replenish fast enough to recover.Seems there can be a problem with the secondary well where the gas rushes up and floods a little,but I can't quite remember the particulars about having that problem.I've seen lots of people that took their carbs all apart,and cleaned them,but didn't take out the secondary well.I've had to drill quite a few of them out.Use a 3/8 drill,reverse spiral,and at some point during the drilling the well will spin itself out.

Re: Carburetor question
 

A Model A Zenith carburetor by design should not stall at a stop. Five million Model A's were delivered new. I doubt they stalled at a stop when new.

Most Zeniths today have been molested in one way or the other over the years. If properly restored they will not stall at a stop. There are a lot of things to consider during the restoration process. The fitting of the throttle plate is as important as the proper float level to avoid stalling at a stop.

Secondary wells that are difficult to remove can easily be removed by heating the casting in the area of the well and dunking it in cold water. It will easily unscrew then.

Tom Endy

Re: Carburetor question
 

Totally agree.. Float needs to come down

Re: Carburetor question
 

Yup, a washer under the seat.

Re: Carburetor question
 

Float needs to be adjusted to proper height or get in the habit of using the hand throttle when coming to a stop. Bring it down a notch or two until you have stopped then return it back to the up right position.

Re: Carburetor question
 

Henry Ford KNEW it was a poor design, that's why he CHANGED it.
In unpredictable stop & go traffic, I just set the hand throttle up, a couple of notches. Generally, the better the BRAKES, the more often the STALL--LOL
Bill W.