Manual Choke setup

[WestCoastComet]

I have a plain-Jane Carter YF on my 200. I bought a choke cable from Classic Inlines, but don't have any ideas on how I'm gonna mount it or adjust it to work properly. Right now I have a stove type heater choke on there. Never opens though. Do any of y'all got pics of your own manual choke setup? Any advice or tips would help too. Thanks in advance!

 

[Frankenstang]

Well if you already have the cable from Classic Inlines cable this may not be much help, but for converting from an auto to manual choke I think something like the Dorman kit below is easiest...also pretty inexpensive. I'm not familiar with what the Classic Inlines setup includes.
http://www.jcwhitney.com/choke-conversi ... 05632.jcwx

I think these tend to work best on an auto to manual choke conversion because it makes use of the original linkage piece for the auto choke that hides behind the black cover (if you take the black cover off your thermal auto choke you'll find a linkage arm that attaches to a tang on the end of the thermal coil spring that is part of the cap). Otherwise stock manual choke carbs usually came with an additional bell crank or linkage piece that attached near the top of the carburetor right off the choke butterfly.

You might be able to make your CI cable make use of the current auto choke linkage piece behind the cap or remove the cap & housing. You also could fab or find the upper linkage piece like the original stock manual chokes had.

Another option would be to fix your thermal auto choke. Most of the time these stop working because carbon builds up in the vacuum passages of the carb that draw hot air from the exhaust manifold, up the stove pipe and across the spring causing it to contract and de-choke. This can be fixed by cleaning the vacuum passages. Another possible point of failure is the stove pipe itself being missing, clogged or detiorated.

Hopefully someone else might pop up with more info or pics...BTW Welcome to the Forum! Good luck!

 

[cballard1972]

Thanks for sharing the info FS. I got my auto choke working today. Yeah!!!!

 

[cballard1972]

Well I thought it was. Still not closing on it's own when cold. ????

 

[fordconvert]

I cant remember do these choke stats have a loop or a hook on the coils that hooks to the lever in the housing? If its got the loop make sure its on the lever. If its just the hook make sure its on the correct side. Do you have the heater hose running against the housing?

 

[cballard1972]

mine has hook. Which side of the spring does it go on??

 

[mugsy]

Making the choke system work is fairly simple and straight forward. When I bought my Stang from a guy in NC he had dorked around with it so much it didn't function properly. Here's what I found and how I fixed it:

1) There is an internal passage thru the carb that goes to the base that sucks in the hot air. This passage has to be free and clear. The one on mine wasn't, so I cleaned it. When was the last time your carb was rebuilt?

2) The junk in the passages of my carb looked like road grime. So make sure the inlet to the tube is protected from dust, junk, crap flying around the engine compartment. After putting headers on my engine I made a new choke tube and put the open end way down near the collector between the pipes.

3) The tube MUST have some type of insulation. The cooling/radiator fan flows enough air to cool the heated air being suck thru the tube to delay and retard the opening.I put some insulation from another choke tube over the one on the Stang and the choke coil opened properly.

4) I used one insulated choke tube from a JY carb and the choke wouldn't open all the way. I gently removed the insulation and found holes in the tube. So make sure the tube is solid and the only "inlet point" is on the end.

5) Make sure the open end is touching the exhaust system or the tube is contact with it. Heat transfer is related to the area, so get as much contract as possible.

6) Set the choke coil while "cold",so go out to the car and before you fire it up, loosen the little bolts and rotate the housing so the choke plate JUST closes. You might have to have the throttle slight open with your other hand to have the choke rotate freely. More tension on the spring will delay opening. And if the plate doesn't close fully it might open prematurely. Also you will more than likely have to fiddle with it some more depending on how fast or slow the choke pulls off. But that will be a great first starting point.

7) Carbs have the greatest problems functioning in the 45-35F range. Its cold, but not really cold enough. Any changes you do to make the carb run in this temp range will probably have to be re-adjusted when it gets warmer or colder. I'm not saying to WON'T function, it just that the carb has the most difficulty in this range. So if the carb is a little finicky in this range just be aware it's the nature of the beast.

 

[cballard1972]

Thanks mugsy

 

[Frankenstang]

Only thing I'd add to mugsy's very thorough and good info is that I don't think the choke will close completely after it's turned off and sat long enough, unless you give the throttle that initial pump from a cold start. This allows the linkage to 'free' the choke to close and the fast idle screw to return to it's correct postition on the fast idle cam.

EDIT: I don't have a thermo cap with spring that I can look at but IIRC the coil spring will contract when heated, again IIRC (this is in regards to which side of the tang/loop the choke link should be on). In regards to TJ's thoughts; I believe mine was a loop instead of just a tang, so you might want to make sure yours is not broken...it will have to maintain good contact with the butterfly link in order to rotate it correctly back and forth.
Good luck!

 

[mugsy]

FrankieS is correct: you need to press the gas pedal all the way to the floor to "set" the choke. It will not return to the closed position unless the throttle is moved. Also by pressing to the floor you are getting a shot of raw fuel from the accelerator pump below the throttle blade(s) into the intake. That helps with the starting.

I'm also assuming that the high idle, normal idle and idle mixture screw are all functional and set properly.

 

[ludwig]

Note also that there will be about 1/8" of open space when between the choke blade and the the carb throat. If it closes all the way, you only get flooding, not choking. There has to be some air for the gas to burn.

 

[mugsy]

The choke plate should "crack" open when the engine starts that is true. But it should be closed when the engine is sitting still or during cranking. It should be closed while cranking so it give full vacuum to the venturi area; anything to get gas down the throat. But when the engine does fire the choke plate needs to open. Typically the opening amount is part of the carb specification. My 1940 carb has a small vacuum dashpot that pulls the choke plate open the specified amount. The 1100 have a spring that gives the proper tension on the choke plate when the carb is in high idle. The rushing in air versus the spring tension will determine the opening amount. I want to say that YF use the spring loaded choke plate similar to the 1100.

 

[ludwig]

All true, Mugsy. Every shop manual I've seen makes a big deal out of the choke plate standing off the throat 1/8" and using a drill bit for a feeler gauge to get the adjustment. On the 1100, it has to do with the choke pulloff spring tension. You don't want to pin it to the side; just kiss it so it will pull away.

 

[mugsy]

Yup, you have to rebuild a carb while "static" but some of the tolerances are critical in a "dymanic" mode. And it really is the dynamic mode that is important. Personally I didn't like the manual choke I installed and hope I can help the OP keep the auto choke on his carb. Both work if set up and operated right though.

 

[ludwig]

Roger that. I get great results with the stock setup and aftermarket heat riser. The important thing is to make sure all the slides and levers move freely and that the spring and pivot are moving properly. Ultimately you have to make sure it is adjusted properly.

That is the hard part because, in order to do so, you have start with a cold engine and let it warm up to get the pulloff just right. And if it is not, you have to wait until it cools off completely again. Best case, the next [cold] morning. If you get the cams and screws and slides all sorted out, you fiddle with the black cap. More than anything, you need to make sure the tab on the spring is connected to the cap and doesn't come off. AND you have to make sure the loop on the spring actually GOES ON to the pulloff tang on the side of the carb.

By the way, if you are or have been using the stock configuration, where heated air is drawn up through a hole in the manifold at cylinders 3 and 4, the divider inside is often burned out. This causes the tube to suck in hot exhaust and soot, which will melt the cap or foul the insides so that nothing slides freely. The aftermarket heat riser solves this problem and can be attached to the stock manifold as well.

 

[WestCoastComet]

Thanks mugsy, frankenstang, cballard, ludwig, ford convert. Yeah I have the tube running from between 3-4 on my stock manifold. Love your headers ludwig. I see how you have yours set up. My passages should be clear I had a guy rebuild it less than 1000 miles ago. My metal heat tube cracked in half so I figured I'd convert to manual. Perhaps I'll leave it as auto if I can get a new tube set up on there. Does this tube just suck unfiltered air into my carb though? I didn't like that set up because of this reason. It seems too hot down there to put any type of cloth or paper filter on this line. I'm still not sure. Fortunately one of my lifters decided it didn't wanna be quiet so I have lots of time to sit on my butt and think about these things. Thanks for the pic ludwig.

 

[ludwig]

You can get the same thing DIY with a long piece of flexible 1/4" tubing. Flare one end and secure it to the carb with the stock nut. Then wrap the other end around your manifold 3 or 4 times. If you leave the loose end sticking up, you can secure some kind of heat tolerant filter medium or a little bitty filter can on to it. However, that small amount of unfiltered air is nothing compared to what goes in the snorkel.

 

[mugsy]

I went to a JY and got a tube from another carb; I used the insulation off that tube for mine. Its high temp rated, fits the tube OD and did the job. And cheap too.