Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Ford 9N, 2N & 8N Discussion Forum

Spark plug and carburator question...

Welcome Guest, Log in or Register

03-23-2006 07:53:08

Report to Moderator

Tractor has been humming along. Working good.

Do have a couple questions though on possible improvements.

The spark plug closest to the seat (#3 I think) really fouls easily. By fouling I mean lots of gas and debris. New set of spark plug wires would also help I would imagine.

Has been slow starting a couple times. Assumed because it was flooded.

I was using Autolite 216 recommended at Advance Auto. Worked okay. However, in a previous post by Dell and others, you guys recommended a spare set to swap out and Autolite 437.

The new Autolite 437 work great. It was explained to me that the number is only a refernece to the ceramic heat resitance and has nothing to do with how hot they spark.

Could there be a probelm with me using the 216?

What is the difference between the two?

Also, the screw on the carburator is only an idle adjustment and not impacting when running in gear does it?

How do I gauge when I have the idle set correct?

Thanks again to all you guys. You guys are a wealth of knowledge to someone like me who really is not electrically or mechanically inclined.

[Log in to Reply]   [No Email]

03-25-2006 12:01:05

Report to Moderator
 Re: Spark plug and carburator question... in reply to TRCTRMAN, 03-23-2006 07:53:08  
I may be reading wrong but I believe plug closest to seat is #4. Check to see if the plug wire are connected correctly. FWIW

[Log in to Reply]  [No Email]

03-23-2006 08:48:09

Report to Moderator
 Re: Spark plug and carburator question... in reply to TRCTRMAN, 03-23-2006 07:53:08  
The 437 is a higher heat range than the 216.. that extra heat helps keep the tip clean and free from deposits. And no.. it doesn't otherwise effect spark. however.. If this is an old machine.. you probably need metal core spark plug wires.. not modern carbon core.. etc.

Black/sooty is rich - fuel fouling.. oily dirty black is generally a OC ring problem... the 437's might help anyway.. can't hurt.. cheap to try...


[Log in to Reply]  [No Email]

03-23-2006 08:47:29

Report to Moderator
 Re: Spark plug and carburator question... in reply to TRCTRMAN, 03-23-2006 07:53:08  
Well first off if you have one of the Ns, 9,2,or 8N it has 4 cylinders. As far as the plugs, most of the time the larger the number the hotter the plug is but in this case that may not be true since the 2 types are in differant classes of plug but still could be your problem. On the carb you should have 2 adjustments. One of them is up close to where it bolts on the manifold and thats the idle setting and then theres one taht angles and is lower on the carb and thats the main jet and effects how much power the tractor has and if set wrong will cause plugs to foul. The setting on the main jet should be some where between 1-2 turns out from bottom.

[Log in to Reply]  [No Email]

03-23-2006 08:46:17

Report to Moderator
 Re: Spark plug and carburator question... in reply to TRCTRMAN, 03-23-2006 07:53:08  
The "heat range" of a spark plug is not about a "HOT" spark.

Heat range refers to how well the heat from the insulated electrode is carried away to the metal housing of the spark plug, and from there to the cylinder head.

In a given engine, a spark plug that is too "COOL", heat range wise, will not get hot enough to burn fouling deposits off, and will foul.

A spark plug that is too "HOT" will get incandescent at the tip, and cause pre-ignition of the fuel charge, before spark occurs, which will cause knock and piston damage.

For a given engine, and also the way you are using the engine, the correct spark plug will be between those extremes.

Typically, a lot of these tractors spend a lot of time putzing around the yard, or whatever, and often are not worked hard for a 12 hour day, as they were when they were someone's main farm tractor.

Therefore, a "hotter" plug works better, because it will heat up enough at the lighter engine loads to burn the tip clean, that's where the "437's" come in.

[Log in to Reply]  [No Email]
Tom N MS

03-23-2006 08:14:00

Report to Moderator
 Re: Spark plug and carburator question... in reply to TRCTRMAN, 03-23-2006 07:53:08  
See if this helps from Mr. Dell
Dell (WA) 12-17-2005 09:45:24

Report to Moderator

Well John..... ...I could suggest you do a "search" of the "archives" of this great N-Board but I won't. Much to the dismay of the environmental bureaucrats, ALL CARBS must be adjusted to match their engine. Each engine and each carb flows (mixes gas) slightly different, but they are ALL ADJUST the same way. MAXIMUM IDLE RPM's, understand? Don't matter, 4-barrel belchfire V-8s, exotic multi-carb 12-cylinder sportscars, 4-cylinder ricerockets, or M/S carb'd N-Tractors; maximum idle rpms.

The M/S is slightly different because it has an adjustable MAINJET, automobile carbs have "fixxed" internal mainjets that are replaceable. But thats another completely different subject and technique.

Both Ford and Marvel/Schebler say to adjust BOTH the SIDE-pointing idlemix needle and the DOWN-pointing mainjet needle to 1-turn to start with. I adjust the down-pointing mainjet to 1-1/2 turns and LEAVITT!!!

I then adjust the side-pointing idlemix for maximum idle rpms, NOT SMOOTHEST idle, max idle rpms. Understand? I then adjust the behind the carb throttle idlespeed screw for a SLOOOooow 400rpms. (ennnythang under 500 is probably close) I do that song & dance 3-times, always adjusting for maximum idle rpms. Understand? My idlemix ended up about 3/8 turn, (last time I counted) yours will be different.

Remember the side-pointing idlemix is BASSACKWARDS; out for lean, IN for ENRICH..... ...HTH, Dell

[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:

We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums

Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy