not running well: carb?

1938 F20 · Nov 12, 2008

I got a 38' F20 last week. Had it running good for a few hours, than decided to fix a seeping old block repair. Got that done Monday, went to use it today & it fired right up, but, when I released the choke rod, it died. Pulled the choke, cranked it over, started up again & same thing, will run w/ choke, but dies as soon as the rod is released. I repeated this a dozen times trying to give it more/less fuel (always w/ same result). I'm assuming my carb needs to be cleaned (I haven't touched it yet), any other ideas before I pull it & clean it? thanks

ScottyHOMeY · Nov 12, 2008

Did you pull the manifold to deal with the block repair? If so and nothing else changed, it sounds suspiciously like a vacuum leak at the manifold letting too much air in.

1938 F20 · Nov 12, 2008

Thanks for response, I didn't touch the manifold, repair was lower, see pic

http://i464.photobucket.com/albums/rr4/kennebunksawmill/blockrepair002.jpg

1938 F20 · Nov 12, 2008

....anyone ever work on one of these carbs? We are very familiar w/ the letter series carbs, but , this one is obviously quite different...anything I should know before I pull it apart? I'll start work on it tomorrow after work. thanks again

Dellbertt · Nov 12, 2008

You got some crud in the line. Clean the whole thing from the tank to the carb. Install a screen in the tank at the top of the sediment bowl if it has one.

Tony S. · Nov 12, 2008

How"d you do the block?

Andy Motteberg · Nov 12, 2008

Could be the carb just needs a rebuild, but also check the fuel flow to the carb and make sure there is a good clean flow of fuel to the carb. There is a fuel filter screen on the carb, make sure it is clean. If you have a in-line fuel filter, remove it. The carb is pretty easy to rebuild, if you purchased a kit, it should include instructions. The venturi in the F-20 carb needs to be put in a certain way, there is a notch in it that needs to line up with another notch in the carb. Instructions should say it all, but post here if you have any more questions. I see your block is repaired, did you use JB weld? How long is the crack? My F-20 has a cracked block too, I put on JB weld for now. The crack in my F-20's block is very long, the crack goes all the way onto the water pipe mounting surface, not good, but it seems to hold the coolant.

Anonymous-0 · Nov 13, 2008

Not positive, but I think that V-belt fan is from a 1939. Check the screen at the carb inlet as well as lines and sediment bowl. Open drain on bottom of carb and check for full flow before taking to much apart.

not running well: carb?

1938 F20

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ScottyHOMeY

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1938 F20

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1938 F20

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Dellbertt

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Tony S.

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Andy Motteberg

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Anonymous-0

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