Pulling Forum - Carberator

Print Page | Close Window

Carberator

Printed From: Unofficial Allis
Category: Other Topics
Forum Name: Pulling Forum
Forum Description: Forum dedicated to Tractor and Garden Pulling
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=211834
Printed Date: 16 Sep 2026 at 1:04pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Carberator

Posted By: Stoges
Subject: Carberator
Date Posted: 29 Jul 2026 at 3:05pm

I have a M-S 853 carb on E3, running rich at an idle, 10 on a AFR gauge. Carb was rebuilt by a “professional “ I have no control with the idle jet, any ideas on what’s wrong.

The load jet is fine, AFR runs 13.5 tuned on a dyno Opened to ideas. Thanks Bill

Replies:

Posted By: DrAllis
Date Posted: 29 Jul 2026 at 3:55pm

What does it do if you unscrew the idle mixture jet and remove it ?? All the way in is rich. All the way out/removed is letting in air. Normally 1 1/2 turns out is very close. So, if it still does it with the jet removed there must be a plugged internal passage or jet not allowing air into the idle circuit.

Posted By: Stoges
Date Posted: 29 Jul 2026 at 4:30pm

Closed it will die, take out makes no difference, it’s not getting air I think now. Can you get to all the passages. I have rebuilt JD, I have all carb cleaning tools just never tackled a M-S

Posted By: DrAllis
Date Posted: 29 Jul 2026 at 6:49pm

Did it idle fine before it was worked on ?? Should be able to get to all passages and jets but when they're 60 years old what could go wrong .....

Posted By: Stoges
Date Posted: 29 Jul 2026 at 11:30pm

it has always idled fine but the plugs are carboned up but ran good never fouled. I put a AFR gauge on and it shows it running rich at 10 and will foul the sensor. That’s when I tried to lean it out but no response. Timed at 23 degrees by a ligh and verified with a vacuum gauge. Thanks for your help Doc, I built the motor two years ago pretty much to your guiding lines..