JohnnyMaryjo Posted August 22, 2022 Share Posted August 22, 2022 The idol on my 1 barrel carb. flat head 6 is to high I tried to set it lower with the set screw but it came all the way out. and the idol is still running to high. here is a pic of the linkage can I do anything with the linkage to lower the idol on the car.if so please tell me how I had someone do this work for me only to find out he had less knowledge than me please help thanks Johnny Link to comment Share on other sites More sharing options...
TerryB Posted August 22, 2022 Share Posted August 22, 2022 (edited) Johnny, it looks like the gas pedal linkage rod that connects to the carburetor is threaded on the end. If it is, you can undo the pin that secures it to the carb and then turn that piece on the threaded rod toward the end of the rod. That should add some slack and hopefully slow down the idle. I circled the part. And it’s the idle adjustment you are working to correct😀. Edited August 22, 2022 by TerryB (see edit history) 1 Link to comment Share on other sites More sharing options...
Rusty_OToole Posted August 22, 2022 Share Posted August 22, 2022 Air leak somewhere. If not the idle adjustment or throttle held open could be badly worn throttle shaft, loose bolts on intake manifold, defective gasket, anything that allows air in. Link to comment Share on other sites More sharing options...
TerryB Posted August 22, 2022 Share Posted August 22, 2022 1 hour ago, Rusty_OToole said: Air leak somewhere. If not the idle adjustment or throttle held open could be badly worn throttle shaft, loose bolts on intake manifold, defective gasket, anything that allows air in. He said it’s a newly rebuilt carb. Link to comment Share on other sites More sharing options...
TerryB Posted August 22, 2022 Share Posted August 22, 2022 (edited) Take a photo for me of the idle speed screw you were adjusting. There is an idle mixture screw and an idle speed screw on the carb. I want to make sure you are adjusting the speed screw. The idle speed screw is located near where the pedal linkage connects to the carburetor. Edited August 22, 2022 by TerryB (see edit history) 1 1 Link to comment Share on other sites More sharing options...
Rusty_OToole Posted August 23, 2022 Share Posted August 23, 2022 6 hours ago, TerryB said: He said it’s a newly rebuilt carb. And yet somehow it won't idle. How many times have we tried to solve a problem that turned out to have some off the wall cause that the OP failed to mention. Rebuilt by who? Rebuilt how? I would go over it looking for air leaks etc and if nothing turned up, would suspect the rebuild was faulty. Link to comment Share on other sites More sharing options...
Oldtech Posted August 23, 2022 Share Posted August 23, 2022 You definitely need to do as TerryB says and check the linkage that it is not holding the throttle open. If the throttle lever is all the way to the screw stop and it is still fast then either there is a leak or the throttle plate isn't correctly installed. It's a pretty simple setup. time to study it and learn a little older tech. Link to comment Share on other sites More sharing options...
carbking Posted August 23, 2022 Share Posted August 23, 2022 Is the throttle return spring in place? Carburetor is a Chrysler-design where the normal "idle" is about half throttle, and the RPM is decreased by the throttle return spring. If the return spring is not present, nothing you do to anything else will bring down the idle. Jon. 3 Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted August 28, 2022 Author Share Posted August 28, 2022 On 8/22/2022 at 11:39 AM, JohnnyMaryjo said: The idol on my 1 barrel carb. flat head 6 is to high I tried to set it lower with the set screw but it came all the way out. and the idol is still running to high. here is a pic of the linkage can I do anything with the linkage to lower the idol on the car.if so please tell me how I had someone do this work for me only to find out he had less knowledge than me please help thanks Johnny I looked at that it is a spring there is no thread under the spring to do what you asked me any other ways to decrease the idol Link to comment Share on other sites More sharing options...
TerryB Posted August 28, 2022 Share Posted August 28, 2022 10 minutes ago, JohnnyMaryjo said: I looked at that it is a spring there is no thread under the spring to do what you asked me any other ways to decrease the idol The screw with a smallish spring around the threads and located near where the gas pedal linkage is attached to the carburetor is an idle speed adjustment. The other spring discussed is a much larger spring that is used to put tension on the gas pedal linkage to make sure the gas pedal returns when you lift your foot from the gas pedal. The big spring keeps the throttle linkage in tension so it closes the throttle. That big spring needs to be doing it’s job so that you can make idle speed adjustments with the small screw. Link to comment Share on other sites More sharing options...
carbking Posted August 28, 2022 Share Posted August 28, 2022 (edited) Here are two pictures of a Chrysler design (the rusted throttle body) and a Carter-design as the carburetor sits WITH NO EXTERNAL FORCE APPLIED (picture 1). Note the Carter throttle valve is closed, and the Chrysler throttle valve is about 1/2 open! You can see the space between the throttle plate and the throttle bore. Under this condition, idle would be about 2000 RPM! Now look at the second picture, where I have simulated the action of a throttle return spring that would normally be attached to the throttle arm. Now the Chrysler design is closed like the Carter design. Jon Edited August 28, 2022 by carbking (see edit history) 1 Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted August 28, 2022 Author Share Posted August 28, 2022 4 hours ago, TerryB said: The screw with a smallish spring around the threads and located near where the gas pedal linkage is attached to the carburetor is an idle speed adjustment. The other spring discussed is a much larger spring that is used to put tension on the gas pedal linkage to make sure the gas pedal returns when you lift your foot from the gas pedal. The big spring keeps the throttle linkage in tension so it closes the throttle. That big spring needs to be doing it’s job so that you can make idle speed adjustments with the small screw. I Am so sorry I have no idea as to what you are saying to me this is why I was hoping that there is someone in my area to come and figure this out Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted August 28, 2022 Author Share Posted August 28, 2022 3 hours ago, carbking said: Here are two pictures of a Chrysler design (the rusted throttle body) and a Carter-design as the carburetor sits WITH NO EXTERNAL FORCE APPLIED (picture 1). Note the Carter throttle valve is closed, and the Chrysler throttle valve is about 1/2 open! You can see the space between the throttle plate and the throttle bore. Under this condition, idle would be about 2000 RPM! Now look at the second picture, where I have simulated the action of a throttle return spring that would normally be attached to the throttle arm. Now the Chrysler design is closed like the Carter design. Jon I am so sorry I have no idea as to what you are saying to look at I know nothing about linkage and carbs. was hoping someone could come and work on this I have had a few people who tried but ended up making it worse. the idol is now to high the linkage i think is wrong, the original linkage that was on this was taken off and so called tossed out plus the when the throttle is kicked down it chokes and wants to stall . is there anyone in the Ohio W.Vir. Pa area that can make a house call and make it right ? thank you Johnny Link to comment Share on other sites More sharing options...
TerryB Posted August 28, 2022 Share Posted August 28, 2022 12 minutes ago, JohnnyMaryjo said: I Am so sorry I have no idea as to what you are saying to me this is why I was hoping that there is someone in my area to come and figure this out Understood, I wasn’t sure if you were going back to the problem to try and figure it out. Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted August 28, 2022 Author Share Posted August 28, 2022 1 hour ago, TerryB said: Understood, I wasn’t sure if you were going back to the problem to try and figure it out. maybe if I take pics of the linkage you can circle what to look for 2 Link to comment Share on other sites More sharing options...
nearchoclatetown Posted August 30, 2022 Share Posted August 30, 2022 Gee, if you just disconnect the linkage and run it WITH the spring wouldn't that tell you if the linkage or a vacuum leak were the problem? Link to comment Share on other sites More sharing options...
TerryB Posted August 30, 2022 Share Posted August 30, 2022 1 minute ago, nearchoclatetown said: Gee, if you just disconnect the linkage and run it WITH the spring wouldn't that tell you if the linkage or a vacuum leak were the problem? The unknown is whether the car has a throttle return spring on the linkage. Johnny is very new at old car stuff and isn’t sure his car even has a return spring at this point. Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted August 30, 2022 Author Share Posted August 30, 2022 where would the return spring be on it Link to comment Share on other sites More sharing options...
TerryB Posted August 30, 2022 Share Posted August 30, 2022 I can’t reach my parts book that would be able to help exactly with the throttle return spring location. Looking at pictures on line of 1941 Plymouth cars, I think the spring is on the drivers side of the engine near the oil fill and distributor. The spring is probably about 3 to 4 inches long with one end fastened to a fixed eyelet and the other side attached to a place on the linkage. Also, I found some information on similar carburetors like yours for the idle speed adjustment screw that has been mentioned before. Pictures are attached. Perhaps you can see the screw on your carb. 1 Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted August 30, 2022 Author Share Posted August 30, 2022 Thank you so much for the pics everything looks to be correct except the throttle adj. screw is all the way out and I can not find the fast idle adj. screw looks like there are 2 ? the spring near the pedal is there I really need someone who really knows what they are looking for I do not Link to comment Share on other sites More sharing options...
TerryB Posted August 30, 2022 Share Posted August 30, 2022 Can you please take a picture of the throttle adjustment screws on your carburetor? As I said, my pictures are typical and may not be exactly what yours looks like. A picture of what you have would greatly help. Also, do you have a carburetor choke control knob on your dashboard? Wish I could help in person too! Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted August 30, 2022 Author Share Posted August 30, 2022 2 hours ago, TerryB said: Can you please take a picture of the throttle adjustment screws on your carburetor? As I said, my pictures are typical and may not be exactly what yours looks like. A picture of what you have would greatly help. Also, do you have a carburetor choke control knob on your dashboard? Wish I could help in person too! 2 hours ago, TerryB said: Can you please take a picture of the throttle adjustment screws on your carburetor? As I said, my pictures are typical and may not be exactly what yours looks like. A picture of what you have would greatly help. Also, do you have a carburetor choke control knob on your dashboard? Wish I could help in person too! Thank you so much for the pics everything looks to be correct except the throttle adj. screw is all the way out and I can not find the fast idle adj. screw looks like there are 2 ? the spring near the pedal is there I really need someone who really knows what they are looking for I do not here are the pics for you I do not know if this is or are the pics you need I did take pic of the dash you can see the choke and other knobs I really want to thank you your the best Link to comment Share on other sites More sharing options...
TerryB Posted August 31, 2022 Share Posted August 31, 2022 (edited) Ok, good pictures. I see the throttle return spring and the carburetor screws and the choke knob. If you look at the picture I marked up, the left spring that I circled is the idle speed screw. Turning that screw should change the idle speed. Usually turning the screw counter clockwise will slow down the idle. The brass colored screw on the right side of the picture with a circle around it is the idle fuel mixture screw. To set that screw to the correct adjustment, the screw is turned in clockwise all the way until it stops (no excessive force) and then turn it counter clockwise back out 1 1/2 turns. You can set the idle mixture screw without having the engine running. Remember, you turn it all the way in first and back the screw out 1 1/2 turns. I would set the idle mixture screw setting first before trying to set the idle speed. As the car reaches normal operating temperature you can readjust the idle speed screw as necessary to get the car to idle to about 500 rpms. Hope this helps! Edited August 31, 2022 by TerryB (see edit history) 2 Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted August 31, 2022 Author Share Posted August 31, 2022 thank you I bought a service book Plymouth for my 1941 Plymouth it has most everything .I tried to do what you told me top do but it does help lower the idle a bit turned it to 1 1/2 but the other screw is all the way out I still think the idle is to high cause I can pull out and shift without gas and it will go ? will not stall is that ok ? as for it choking and trying to stall when flooring the gas pedal it is still there I do think it is the carb a friend of a friend has a carb but needs to be sent out for repair do you know who I can send it to ? thank you once again Johnny Link to comment Share on other sites More sharing options...
TerryB Posted August 31, 2022 Share Posted August 31, 2022 For sure the idle is too high if you do not have to give it any gas to pull out. Tell me about cold starting, do you pull out the choke first before starting? When the engine starts with the choke pulled out, does it idle fast? Does the idle slow down when you push the choke back in? I’m still thinking your problem may be with the carb linkage, especially when you say the idle adjustment screw is turned all the way out. Makes me think something is not connected properly with the choke to carb metal cable or something with the gas pedal linkage. Glad to hear you have a shop manual. That is very important to have when trying to fix problems like this. Link to comment Share on other sites More sharing options...
TerryB Posted August 31, 2022 Share Posted August 31, 2022 Looking on line I found this carb shop in Youngstown Oh. I know nothing else about their services but they do have a good on line reputation. https://www.carburetorrestorationyoungstownoh.com/ Link to comment Share on other sites More sharing options...
Grimy Posted August 31, 2022 Share Posted August 31, 2022 (edited) No one has yet mentioned checking the hand throttle--see knob marked "throttle" underneath the amps gauge. That is connected to the carburetor's throttle plate linkage via a Bowden cable (wire inside a spiral-wrapped sheath). Suggest you loosen the lock screw attaching the HAND throttle cable to the carb and pull the wire portion back--to ensure that the hand throttle is not too tight and partially opening the throttle butterfly in the carb despite being pushed in all the way. With the hand throttle cable *really* loose (so that the return spring *should* be keeping the butterfly closed), look down into the carb. You want to see the throttle plate/butterfly fully closed at an angle against the circular wall of the carb. Once you have assured that the throttle/plate/butterfly is fully closed, *then* reattach the hand throttle cable with no slack, but be sure that that cable is not trying to open the throttle when the knob is fully pushed in against the dash. Edited August 31, 2022 by Grimy added last sentence (see edit history) 2 Link to comment Share on other sites More sharing options...
TerryB Posted August 31, 2022 Share Posted August 31, 2022 7 minutes ago, Grimy said: No one has yet mentioned checking the hand throttle--see knob marked "throttle" underneath the amps gauge. That is connected to the carburetor's throttle plate linkage via a Bowden cable (wire inside a spiral-wrapped sheath). Suggest you loosen the lock screw attaching the HAND throttle cable to the carb and pull the wire portion back--to ensure that the hand throttle is not too tight and partially opening the throttle butterfly in the carb despite being pushed in all the way. With the hand throttle cable *really* loose (so that the return spring *should* be keeping the butterfly closed), look down into the carb. You want to see the throttle plate/butterfly fully closed at an angle against the circular wall of the carb. Once you have assured that the throttle/plate/butterfly is fully closed, *then* reattach the hand throttle cable with no slack, but be sure that that cable is not trying to open the throttle when the knob is fully pushed in against the dash. Good observation Grimy! I missed the throttle knob and yes it’s another good thing to check as you explain above. 1 Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted September 1, 2022 Author Share Posted September 1, 2022 22 hours ago, TerryB said: For sure the idle is too high if you do not have to give it any gas to pull out. Tell me about cold starting, do you pull out the choke first before starting? When the engine starts with the choke pulled out, does it idle fast? Does the idle slow down when you push the choke back in? I’m still thinking your problem may be with the carb linkage, especially when you say the idle adjustment screw is turned all the way out. Makes me think something is not connected properly with the choke to carb metal cable or something with the gas pedal linkage. Glad to hear you have a shop manual. That is very important to have when trying to fix problems like this. 23 hours ago, TerryB said: Good observation Grimy! I missed the throttle knob and yes it’s another good thing to check as you explain above. I have tried everything that everyone has told me to try or do.I do not know if I am doing this correctly or not But nothing is working.they tell me it is the carb ? but I have had this carb replaced and kits to the original and no luck where can I take this 1941 Plymouth to get it corrected ? its the high idol ,and anything over 2500 rpm it will spit and choke ? thanks Johnny Link to comment Share on other sites More sharing options...
avgwarhawk Posted September 1, 2022 Share Posted September 1, 2022 I did not see where the base plate gasket was checked to assure it was not interfering with the throttle valve. Link to comment Share on other sites More sharing options...
TerryB Posted September 1, 2022 Share Posted September 1, 2022 Johnny, The throttle cable from the dash connects to the gas pedal linkage and is able to increase the idle by pulling it out like you do for the choke. If the cable is not adjusted correctly it can make the idle too high. See the picture I have attached with markups, that is the throttle cable connection location. If you loosen the screw I have circled, it might make the idle slower. 1 Link to comment Share on other sites More sharing options...
pont35cpe Posted September 1, 2022 Share Posted September 1, 2022 Have you tried disconnecting the linkage at the carb, and running/adjusting carb? This would eliminate all the linkage, and if still won`t slow down, linkage is not the problem. 1 Link to comment Share on other sites More sharing options...
JohnnyMaryjo Posted September 2, 2022 Author Share Posted September 2, 2022 I fooled with that for awhile and nothing still runs high idol .I think it is in the carb but where do I go and buy or have this one rebuilt Who is Good at this thank you once again Johnny Link to comment Share on other sites More sharing options...
TerryB Posted September 2, 2022 Share Posted September 2, 2022 On 8/31/2022 at 11:35 AM, TerryB said: Looking on line I found this carb shop in Youngstown Oh. I know nothing else about their services but they do have a good on line reputation. https://www.carburetorrestorationyoungstownoh.com/ Did you see this? Link to comment Share on other sites More sharing options...
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