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Boy, does my son's slant run crappy! https://slantsix.org/forum/viewtopic.php?t=37475	Page 3 of 4

Author:	'74 Sport [ Mon Oct 26, 2009 5:43 am ]
Post subject:	Update
Well, the mechanic was right, it was missing. Number 3 plug wire was bad. I replaced the terminal inside the plug boot and it has good juice, now. But, that didn't fix everything... The engine started doing the same thing as it did before - dying at idle. I pulled the carb and the brass tube had again fallen out of the venturi cover. I've got another carb to swap over and it should hopefully fix all the recent problems. <fingers crossed> Jerry

Author:	daniel_depetro [ Wed Oct 28, 2009 4:56 am ]
Post subject:
Any updates?

Author:	'74 Sport [ Wed Oct 28, 2009 6:31 am ]
Post subject:
Waiting on the carb to get here - should be in today's mail.

Author:	'74 Sport [ Mon Nov 02, 2009 9:44 am ]
Post subject:	Hooray! It's running again.
Man, what a difference it makes when all cylinders are firing and the carburetor is working as it should! Fixed a plug wire, installed a rebuilt (not reman) carb, did a little quick tuning, and the test drive went great. I still want to set the valve lash, check the timing, replace the rubber fuel lines, tweak the idle settings, and replace the air filter. What should I expect the vacuum reading to be? Right now, it stays at a steady 15 in. at 750 rpm idle.

Author:	SlantSixDan [ Mon Nov 02, 2009 9:54 am ]
Post subject:
What is your altitude above sea level?

Author:	'74 Sport [ Mon Nov 02, 2009 12:52 pm ]
Post subject:
600 - 700 ft

Author:	walpolla [ Mon Nov 02, 2009 1:07 pm ]
Post subject:
comparisons are fun regards,Rod

Author:	'74 Sport [ Mon Nov 02, 2009 1:48 pm ]
Post subject:
Quote: comparisons are fun I guess I'm missing your point, Rod. Are you pointing out the wildly divergent replies that I received from two different forums? I agree, it is interesting to see what the various "fixes" were for folks with their cars having very similar symptoms. Over the years, since beginning this project with my son, I have determined that a single mechanical problem can masquerade in many different disguises. That's what makes it so frustrating, yet so much fun...

Author:	walpolla [ Mon Nov 02, 2009 1:58 pm ]
Post subject:
Quote: Quote: comparisons are fun Are you pointing out the wildly divergent replies that I received from two different forums? I agree, it is interesting to see what the various "fixes" were for folks with their cars having very similar symptoms. yep. regards,Rod

Author:	'74 Sport [ Mon Nov 02, 2009 8:35 pm ]
Post subject:
The choke pull-off on the replacement carb was not holding vacuum, so I replaced it with the working one off the original carb. Their linkage rods were slightly different in shape and length, requiring additional bending. Since there are no numbers on either of the choke pull-offs, can someone provide me with the proper part number for one for a Carter BBD? Are particular brands better than others? Will I need to first determine a model number on the carb?

Author:	SlantSixDan [ Mon Nov 02, 2009 9:47 pm ]
Post subject:
There are multiple different BBD pull-offs that don't interchange. Tell us more about this "rebuilt but not remanufactured" carburetor you installed. Where'd it come from?

Author:	'74 Sport [ Tue Nov 03, 2009 6:13 am ]
Post subject:
Number cast in side of carb is 0-2543, just underneath the "Carter...St. Louis..." I have no complaints about the carb itself, it runs quite well, I'm just having a bit of an issue with the choke adjustment. It came from a member here who had it rebuilt and rebushed. Maybe I'm just being dense, but I don't quite understand what the purpose is for having both a vacuum-operated choke pull-off on the carb and a thermostatically-operated choke on the manifold.

Author:	Reed [ Tue Nov 03, 2009 8:20 am ]
Post subject:
The vacuum operated choke pulloff allows the choke to be completely closed on initial cold startup, allowing the carb to pull a large amount of fuel out of the fuel bowl. As soon as the motor starts, vacuum is applied to the choke pulloff diaphragm and the choke opens roughly (very roughly) .25 inches. This instantly leans out the mixture to avoid an overly rich condition. That is the only function of the vacuum operated choke pulloff. It is essentially an on/off switch to pull the choke open. The thermostatically controlled spring controls the choke movement from fully closed to fully open. The motor needs much more gas to run when cold, but as it warms up it needs less. To allow for this, the thermostatically controlled choke spring is a bi-metallic spring that expands as the motor heats up, slowly pulling the choke open. You need both to allow the motor to get the most fuel on startup, but then to immediately lean the mix out to avoid excessive fuel, and then to slowly lean the mixture out as the motor warms up.

Author:	'74 Sport [ Tue Nov 03, 2009 9:43 am ]
Post subject:
Now, that makes perfect sense! Thanks, Reed. Since it was a warm afternoon on Sunday when Aaron and I installed the "new" carb, we didn't get a good chance to observe much choke action before the engine warmed up (we were also distracted by trying to make idle and mix adjustments). So, this morning while it was cool in the garage, I gave it a try. I pushed the pedal once to set the choke, got out and pulled the air cleaner lid to verify, and noticed the choke plate was not closed. I manually manipulated the throttle and choke to set the fast idle screw on the high ridge of the cam. When I turned the key over, it fired right up, but then began to bog and died. I gave it another try and it did the same thing. I got out to check the choke again and noticed the rod on the pull off had fallen out of its slot in the end of the choke shaft. I reattached it, manually set the choke again, replaced the lid, turned the key again, and it fired up and ran a bit rough until I pressed lightly on the accelerator pedal. As it began to warm up, the rpm increased, but I needed to get to work, so I shut it down. Needless to say, I want to spend a little time checking out the choke and choke pull off adjustments and linkage. That's why I was trying to determine the proper pull off part number. I have the old one I removed, but none of the parts houses have them in stock to match up to without special ordering. By the way, is the number I found on the carb useful? Is that the Model No. for a Carter BBD? Does it indicate what year?

Author:	SlantSixDan [ Tue Nov 03, 2009 11:02 am ]
Post subject:
The number on the side is just a casting number. It doesn't tell anything about the year or application of the carburetor. Carter numbers were stamped on an aluminum tag attached to the carb by one of the bowl screws. If the tag breaks or is lost (which is frequently the case) the carb can no longer be precisely identified. Sounds like you've got some problems with the choke linkage and adjustment - Carburetor operation and repair manuals (and some training movies) are posted here for free download.

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