D17 carburetor/ engine running issue?
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=205922
Printed Date: 31 Oct 2025 at 1:43am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: D17 carburetor/ engine running issue?
Posted By: Hunt4Allis
Subject: D17 carburetor/ engine running issue?
Date Posted: 18 Mar 2025 at 6:59am
| Hi, I have a 19 59 ACD 17 that will start right away but then idles poorly and when I pull the choke lever half to three quarters of the way out it runs perfectly and that goes for At Any throttle level whether I'm driving or not? Here's a couple pictures of my carburetor outside, I've had this apart last year to rebuild it and I also put a inline filter in front of carburetor to eliminate any small junk getting into it so I have a hard time believing that it's got anything in the Jets but it's possible I guess. It says my file is too large to attach pictures so I'll have to work on this and add them when I can figure it out why it won't let me but until then anyone have experience of why this would be happening? |
Replies:
Posted By: DrAllis
Date Posted: 18 Mar 2025 at 7:15am
| Open the main jet 2 or 3 turns and try it. |
Posted By: Hunt4Allis
Date Posted: 18 Mar 2025 at 7:37am
| Okay, all this information was fresh in my mind a couple years ago when I rebuilt the carburetor so can you tell me what the carburetor settings are supposed to be set up as Factory? I feel like I remember it saying to turn the screw all the way in till it just touches and then back it off? |
Posted By: DrAllis
Date Posted: 18 Mar 2025 at 7:47am
| Just do as I said FIRST. |
Posted By: steve(ill)
Date Posted: 18 Mar 2025 at 7:55am
|
I would agree with Dr.. You Main Jet is restricted.. For your photo, if you have a computer, open the photo is PAINT or similar and down size it to 800 x 600 pixels... Most camaras take 4000 x 3000 photos or similar.. your trying to shrink the photo from 5 MB to about 100 kb...... If you have a cell phone i think you can e-mail to yourself, then shink the size of it.... before you download to this site. ------------- Like them all, but love the "B"s. |
Posted By: Hunt4Allis
Date Posted: 18 Mar 2025 at 9:44am
  I was able to upload them after doing as you said. Okay so I will just turn the L-shaped screw circled in green counterclockwise 2 or three turns out correct? The second photo with the choke arm circled in green is where it runs great. |
Posted By: steve(ill)
Date Posted: 18 Mar 2025 at 9:47am
|
yep... thats the screw... but also possible a chunk or rust is stuck INSIDE on the jet.
might also check that you have a GOOD SUPPLY of gas going into the carb... and that choke plate is attached to the shaft and not flopping around in the throat. ------------- Like them all, but love the "B"s. |
Posted By: Hunt4Allis
Date Posted: 18 Mar 2025 at 9:50am
| Okay, yes but I have been running a inline small filter for the carburetor to catch any of these particles. What I really need to do is remove the tank and flush it out but that has not happened yet |
Posted By: Hunt4Allis
Date Posted: 18 Mar 2025 at 3:16pm
| Okay I turned the main jet out three turns and it seems to have fixed that issue but now when I put the throttle all the way down low it stalls and turns off so I'm guessing the idle adjust screw needs to be increased? What should this idle at when correct? |
Posted By: steve(ill)
Date Posted: 18 Mar 2025 at 3:40pm
|
is there a STOP SCREW on the back that stops the throttle shaft from closing off completely .... look where the throttle rod connects to the lever...Screw that in until it touches the throttle arm when at LOW IDLE..
Set your idle screw OUT 1.5 turns from the bottom... if it is way off... thats a good start. ------------- Like them all, but love the "B"s. |
Posted By: Hunt4Allis
Date Posted: 18 Mar 2025 at 8:07pm
| I'm in the house now and not going back out to the Tractor until tomorrow so where you're saying it connects to the throttle Rod is that the same point that the governor connects to? |
Posted By: steve(ill)
Date Posted: 18 Mar 2025 at 8:26pm
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yes... the governor rod connects to an arm that moves the throttle plate... There should be a STOP SCREW that you can adjust to limit the throttle from going completely closed.. ------------- Like them all, but love the "B"s. |
Posted By: Hunt4Allis
Date Posted: 19 Mar 2025 at 6:18am
 So turn this screw in tighter correct?( the screw that I have circled in green is on the back side of the carburetor up against the engine block and it's the only one that I can see that has adjustment) what's crazy is I remember setting all these a couple years ago when I rebuilt the carburetor and added the inline fuel filter in front of the carburetor( do these screws get out of adjustment just by running?) 0250319_075003_Gmail~2_2025-03- 19_06-53-02.jpg" /> And this is the idle adjust screw towards the front of the tractor that I have circled in green that needs to be one and a half turns out from tight correct? Thanks much guys for the info! This will be so much nicer cutting hay with her running good this year hopefully... I have a viable tachometer that I had a guy rebuild so what is it supposed to idle at and the top end RPM be?/18254/Screenshot_20250319_075003_Gmail~2_2025-03-19_06-55-38.jpg[/IMG] 
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Posted By: steve(ill)
Date Posted: 19 Mar 2025 at 8:09am
|
yes... that is the screw that pushes on the throttle shaft ( governor rod) arm and holds the throttle plate slightly open so the motor will idle.. Screw it in a turn and then see what happens... adjust as needed.
yes, the second photo looks like the idle screw Mixture... Screw it in till it touches bottom, then screw out 1.5 turns. ------------- Like them all, but love the "B"s. |
Posted By: ekjdm14
Date Posted: 19 Mar 2025 at 8:25am
|
All the work you mentioned doing a couple of years ago, how many tanks of gas have you run through it in that time? And more importantly when you put the machine up, do you run it out or drain the carb? Modern gas doesn't last but 3 or 4 months before going stale compared to stuff from the late 90s that I've seen still run an engine, also attracts moisture due to ethanol so every chance you could have rust in the bowl just from old fuel if you allow it to sit undrained. The carb settings don't go "off" as such just from running, the "sweet spot" will change over time depending on state of tune up, valves/timing etc but won't vary by more than half a turn unless there's some kind of restriction going on. Also, if your filter is 2 years old then replace that too. Paper filters don't do as well with gravity feed systems IMO anyway, I prefer gauze screens or sintered brass. Not to mention they restrict flow even further if they get moisture in them (again, modern fuel loves to get moisture in it). What I'm saying is, if the tractor ran fine the way it was & then sat over winter or somesuch & now needs over a turn change in any of the settings then I'd suggest ensuring good fuel flow & dropping the bowl to clean everything if you're going to be relying on the machine (you can get them running great by adjusting things way off spec, but if that restriction breaks up/dissolves over time you'll end up running way rich & that's as bad or worse IMO than lean).
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Posted By: Hunt4Allis
Date Posted: 23 Mar 2025 at 5:49am
| Okay I turned the screw in until it would idle at 300 RPM, the throttle response is much better now that I got the main jet adjusted correctly and it also runs much better without using the choke. It seems the idle adjust screw that you said to turn in until it touches and back out one and a half turns was the only one that I had set correctly. Thanks much for the info guys it runs like a champ again( at least compared to how it was) is it worth trying to find tune the adjustments now that I got it running better or just leave it alone? I do use this tractor quite a bit so I wanted to be running the correct mixture so it's not too rich or too lean |
Posted By: DrAllis
Date Posted: 23 Mar 2025 at 7:24am
| Technically, you cannot make it "too rich" because the internal jetting already predetermines the maximum fuel burn rate, which is needed for plowing/discing, etc. You may turn the "L" shaped main jet in 1/4 turn at a time and just use the tractor the way you want to use it. At some point, you will get to that fine line of the engine stumbling a bit when you yank the throttle open and then you have now become too lean. Open it back up 1/4 or maybe 1/2 and quit. BUT, if you go to plowing/heavy loads it should be opened up probably 1 full turn to be sure it is rich enough for max power. Most farmers never continually messed with this setting because the fuel saved on lighter loads wasn't that big of a deal when gas was 15 cents a gallon. Lean settings can burn valves when used for constant heavy loads like plowing. |
Posted By: Hunt4Allis
Date Posted: 23 Mar 2025 at 7:29am
| Okay thanks for the info, much appreciated! |
Posted By: HudCo
Date Posted: 23 Mar 2025 at 10:37am
| i was tought to open it up a few turns and throttle it up to full rapidly and snap it back to idle to clear the crap then turn it back in to the point where it would excellerate without stumble , i would open it up when discing, my grandpa would turn them all back down and get after me for wasting gas for raking mowing and every thing easle |
Posted By: Stanley
Date Posted: 23 Mar 2025 at 5:53pm
|
Steve - Ill I have a 1940 AC B - parade ready. What is an approx. value? good rubber and runs great. Thanks Stanley
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Posted By: steve(ill)
Date Posted: 23 Mar 2025 at 6:00pm
|
Stanley.. price of a tractor is determined by how bad someone wants it.. You can buy a "runner" B in poor conditon for $800. ... might cost you $2000. to rebuild and paint.. Is it WORTH $2800. + your labor when finished ? Normally not.. You can buy some pretty nice tractors model "B" for $2000. - $2500. Depending on location and how bad someone wants it.... thats a good starting point. every now and then you see on that sells up toward $3000. but i dont think that is very common.. here is one in Wisconsin that has been FOR SALE for a MONTH.. still there.  ------------- Like them all, but love the "B"s. |
Posted By: Hunt4Allis
Date Posted: 24 Mar 2025 at 11:39am
| Most of the time this tractor is just used for cutting hay with a 7 ft sickle mower that runs off the rear PTO shaft so I'm not sure if that's considered heavy load or not? |
Posted By: Stanley
Date Posted: 24 Mar 2025 at 5:23pm
|
Thanks for the info on the value of an AC B. Unfortunately I have more than invested. I do realize what I have invested does not establish value. I would probably give $2500 some thought.
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Posted By: DrAllis
Date Posted: 24 Mar 2025 at 5:29pm
| Mowing hay would be considered a "light to maybe moderate" load for most applications. |
Posted By: Hunt4Allis
Date Posted: 25 Mar 2025 at 5:51am
| I figured it would be,thanks again for your help |