wcfb choke...

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May 15, 2011 | 05:34 PM

knockbill

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Burning Brakes

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From: delco pa

wcfb choke...

hi,,,
i'm trying to set up a wcfb carb,,, i can set teh choke so it is closed when teh engine is cold, but i can't get it to open as it warms up,,,, my thoughts,, choke thermo spring in backwards, or wrong spring....any thoughts out there?
thanks in advance,,
john

May 15, 2011 | 05:51 PM

midyearvette

Le Mans Master

Joined: Nov 2008

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From: columbus oh

Quote:

Originally Posted by knockbill

is teh heat tube installed from teh exhaust manifold or is it controlled by another heat source to teh thermo coil??

May 15, 2011 | 05:55 PM

knockbill

Thread Starter

Burning Brakes

Joined: Jul 2010

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From: delco pa

Quote:

Originally Posted by midyearvette

is teh heat tube installed from teh exhaust manifold or is it controlled by another heat source to teh thermo coil??

it has a new tube and the piston and cylinder are clean...

May 15, 2011 | 06:05 PM

1snake

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From: Puget Sound

Is there heat being drawn into the choke housing? If not, the vacuum source is plugged.

Jim

May 15, 2011 | 06:21 PM

knockbill

Thread Starter

Burning Brakes

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From: delco pa

Quote:

Originally Posted by 1snake

Is there heat being drawn into the choke housing? If not, the vacuum source is plugged.

Jim

i don't know,,, how can i check ?

does teh piston open the choke as it warms up, and teh thermo spring push it close when it cools? if i open it manually as it warms up, teh therm spring closes it as it cools....

May 15, 2011 | 09:28 PM

1snake

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From: Puget Sound

Quote:

Originally Posted by knockbill

Feel the steel pipe where it enters the choke housing. It should get very hot. The spring tension in the coil closes the choke, engine vacuum tries to open it and when the coil gets hot, it loses its tension and vacuum wins, therefore fully opening the choke.

Jim

May 16, 2011 | 02:12 PM

rengawdor

Racer

Joined: May 2008

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From: Beaver Falls Pa

This manual gives a good description of how the entire choke system operates:

http://www.carbkitsource.com/carbs/t...fb-service.pdf
(Starting on page 9)

Good luck!
Rod

May 16, 2011 | 02:34 PM

66jack

Team Owner

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From: CA

Quote:

Originally Posted by knockbill

Maybe the spring is not even on the "pin" to open and close the choke.

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May 16, 2011 | 03:33 PM

rongold

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From: Putnam Valley, New York. Amateur Radio Operator K2NS

Vacuum ???

Quote:

Originally Posted by knockbill

i don't know,,, how can i check ?

Remove the heat tube from the carb. Start the engine and put your finger on the nipple that the choke tube screws onto. You should feel a slight amount of vacuum there. If not, you either have a clog somewhere or a vacuum leak in the choke housing (cracked housing, missing gasket, etc.)

RON

May 16, 2011 | 03:34 PM

#10

Pilot Dan

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From: NJ Hockey beer league

Quote:

Originally Posted by rengawdor

This manual gives a good description of how the entire choke system operates:

http://www.carbkitsource.com/carbs/t...fb-service.pdf
(Starting on page 9)

Good luck!
Rod

(Great manual link Rod, thanks) Take a look at the figure on p.11, it shows the proper orientation of the thermospring to the choke finger. Notice it is to the right of the finger. As the engine warms up, the spring expands (relaxes) and allows the choke to open fully with the aid of the vacuum piston pulling down.

May 16, 2011 | 03:56 PM

#11

knockbill

Thread Starter

Burning Brakes

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From: delco pa

Quote:

Originally Posted by 1snake

thanks for teh reply.... if teh spring closes teh choke on cool down,,, then teh spring is installed properly.... that leaves teh piston/ vacuum side to look at...
tahnks again
john

May 16, 2011 | 04:00 PM

#12

knockbill

Thread Starter

Burning Brakes

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From: delco pa

Quote:

Originally Posted by rengawdor

This manual gives a good description of how the entire choke system operates:

http://www.carbkitsource.com/carbs/t...fb-service.pdf
(Starting on page 9)

Good luck!
Rod

thanks fro the reply.... i forgot i have that manual!!!!! its tough getting old.....

May 16, 2011 | 04:01 PM

#13

knockbill

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Burning Brakes

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From: delco pa

Quote:

Originally Posted by 66jack

Maybe the spring is not even on the "pin" to open and close the choke.

tahnks for the reply... it is, i mentioned,if i open it manually, teh spring will close it.

May 16, 2011 | 04:03 PM

#14

knockbill

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Burning Brakes

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From: delco pa

[QUOTE=rongold;1577630589]Remove the heat tube from the carb. Start the engine and put your finger on the nipple that the choke tube screws onto. You should feel a slight amount of vacuum there. If not, you either have a clog somewhere or a vacuum leak in the choke housing (cracked housing, missing gasket, etc.)

thanks for the reply....
good info,,, should it read on a vacuum gauge?

May 16, 2011 | 05:15 PM

#15

65GGvert

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From: Kannapolis NC

On a side note. I think the "e" and "h" are reversed on your keyboard.

May 16, 2011 | 06:14 PM

#16

knockbill

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Burning Brakes

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From: delco pa

Quote:

Originally Posted by 65GGvert

On a side note. I think the "e" and "h" are reversed on your keyboard.

i don't know... seems to be that way on any keyboard i use!!!!!!!!!!!!!!

May 16, 2011 | 07:41 PM

#17

DZAUTO

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From: Mustang OK

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Quote:

Originally Posted by knockbill

i don't know... seems to be that way on any keyboard i use!!!!!!!!!!!!!!

Sooooooooooooooooooooo, does that mean you don't proof read your comments before submitting?????

Tom Parsons

May 18, 2011 | 04:13 PM

#18

knockbill

Thread Starter

Burning Brakes

Joined: Jul 2010

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From: delco pa

thanks to those that sent info ....

i started teh engine this morning, and it went right to fast idle, and the choke opened smoothly, in a few minutes,,,teh engine idled down, and the secondary lock out released,,,

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