# choke



## Topkat (Sep 9, 2010)

HI gang
I hooked up 12vdc to my electric choke and ran the car.
from pre start up thru a 10 minute idle, neither plate changed position.
the shaft on the dashpot(?) did pull all the way in but nothing up top moved
it seemed that the dashpot was keeping the secondary plate in the rear closed

What exactly is SUPPOSED to happen?
are both plates supposed to open?
thanks as always


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## freethinker (Nov 14, 2009)

Topkat said:


> HI gang
> I hooked up 12vdc to my electric choke and ran the car.
> from pre start up thru a 10 minute idle, neither plate changed position.
> the shaft on the dashpot(?) did pull all the way in but nothing up top moved
> ...


did the choke element get hot? the choke should be adjusted so it is just closed cold. then when you start the car the vacuum dashpot takes over and opens the choke just enough to get a rich fast idle. then the electric element slowly heats the choke spring up and opens the choke all the way.


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## likethat (Oct 5, 2007)

I see full open choke and the ability for the secondaries to open. The smaller one toward the front of the engine is to open from the electric choke. That is one nice looking carb!


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## BearGFR (Aug 25, 2008)

Hey TK, looking at your photo and reading your description, I think there might be some confusion about what all those parts are. I think the 'dashpot' you're referring to (near the right in the photo, on the front of the carb) is actually the secondary vacuum pulloff - it's got nothing to do with a choke. There's not a choke on the secondaries --- only on the primaries, and in the photo it's already fully open. The plates on top of the secondaries are actually the secondary airvalve - they're supposed to be closed all the time unless the engine is running, under load, and you've got your foot in it enough to open the secondaries. The purpose of the dashpot is to hold the secondary air valves closed most of the time, until you step on it --- when you do that, manifold vacuum drops to near zero and the vacuum inside that dashpot will bleed off through a calibrated orifice, relaxing that link that holds the air valves shut, and allow them to open. Since in the photo the motor isn't running, there's no vacuum on the pulloff so it's "relaxed" and not holding the airvalves shut. What's holding them shut is the air valved tension spring. They won't open unless the engine is running and "pulling" on them with enough air flow to overcome the spring tension and force them open. That's one of the cool things about a QJet - when everything's calibrated and adjusted right, those air valves are going to open just enough to allow the engine to get all the air it wants, but no more. That keeps air flow velocity high through the carb so that all of its various circuits work well.

Bear


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## likethat (Oct 5, 2007)

Looks like 2 open ports on the backside of the carb also. Are they capped or plugged into anything when you are running the car with the air filter pan off?


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## Topkat (Sep 9, 2010)

the 2open ports were that way when I got the carb and nothing goes to them.do I need to cap them.The stud you see is hollow and also a vac port
I get it about the rear one,but is the front one supposed to be closed when the motor is cold? and or when I first turn the key on?
out of the box ,and installed it was all the way closed, after first starting it, running or not, it has not moved. I was just out there and it's still wide open and didnt move when I turned the key.
it has 12vdc on it...what gives?
:confused
thanks you!


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## BearGFR (Aug 25, 2008)

Topkat said:


> the 2open ports were that way when I got the carb and nothing goes to them.do I need to cap them.The stud you see is hollow and also a vac port
> I get it about the rear one,but is the front one supposed to be closed when the motor is cold? and or when I first turn the key on?
> out of the box ,and installed it was all the way closed, after first starting it, running or not, it has not moved. I was just out there and it's still wide open and didnt move when I turned the key.
> it has 12vdc on it...what gives?
> ...


Normally once they open, they won't close again - even with a cold engine - until you step on the throttle and release it. It's because the throttle stop screw that's sitting on the fast idle cam is holding the choke in position. When you step on it, it moves the screw off the cam and lets the mechanism move. Try that - see what happens. If it still doesn't close, Sum-Ting-Wong --- look for problems around the fast idle cam linkage.

Bear


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## likethat (Oct 5, 2007)

I would cap all unused ports.


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## Eric Animal (Oct 28, 2007)

:agree:agree:agree


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## BearGFR (Aug 25, 2008)

So would I.


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## facn8me (Jul 30, 2011)

The three screw on the side of the choke is what adjust tension. If cold Throttle moved and the choke plate does not shut. You need to loosen the three screw and rotate the black plastic with power wire attached untill the choke plate starts to close. If it's to tight it will cause it to run rich after running a few. Too loose and will cause it to stumble/die on acceleration til warm. The choke pull off can be adjusted for how far the choke plate will open when cold and running with spring tension on the choke.


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## Rukee (Feb 8, 2007)

I usually run the key'd choke wire through a 2 prong oil pressure switch so then the choke only gets power when the engine is running. That way if your working on the car with the key on but the motor not running, your not warming up the choke stat.


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