Engine Stalls/Floods after Warm

[Norm]

First of all, I am a carburetor novice. I have a 1950 Olds 88 (Rocket 8 303 w/ Rochester AA carb). Car starts fine and idles fine at high idle and does so for quite some time. Once I kick it down to low idle, it stalls and gasoline spills from the carburetor. I’ve checked the needle and float and they seem fine. What else should I check? Power Valve? Some adjustment? Thanks for any ideas.

Topic

[college man]

see if this helps.

http://www.carbkitsource.com/carbs/tech/Rochester/AA-index.html

[Bill]

The only thing that controls the fuel level in a carburetor is the float and needle and seat. The problem should be in that area. Check to make sure the float does not have fuel inside. Remove it and shake it beside your ear. You should be able to hear and feel if there is fuel inside. That would make the float heavier and not close the needle tight against the seat. The float level needs to be adjusted properly also.
In rare instances I have seen fuel pump diaphragms swell and cause higher than normal fuel pressure that overcomes the capability of the needle to shut the fuel off. A fuel pressure gauge would verify that.

[Norm]

Thanks for the suggestions. I should also have mentioned that the carb was professionally rebuilt a few years ago before I bought the car so it looks like new. I do know that it still has the original steel needle though as I believe the needle that came with the kit did not seal well. The car has been running great for the past year until it stalled for the first time a week ago. I just received a replacement needle which I’ll try tomorrow and will double-check the float adjustments also.

[Author]

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