TRACTOR PARTS Allis Chalmers Case & David Brown Farmall & International Ferguson Ford & New Holland John Deere Massey Ferguson Massey Harris Minneapolis Moline Oliver & Cockshutt Kubota / Yanmar

TRACTOR MANUALS

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

Attention Forum Users: On the 28th of December 2023 at 9:00am Central Time, we will be taking the forums down for maintenance while we prepare the new forums for your use. Please click here for more information.

John Deere Tractors Discussion Forum

40 not running right

Welcome Guest, Log in or Register

Author

Apexdeere

06-03-2007 05:56:37

Report to Moderator

Gotta problem. I have rebuilt a model 40, including new pistons, rings, bearings, valves, etc. Started her up, ran like a charm. Took her on a tour of the farm, but about 45 minutes into the ride, she started back-firing, missing, just sounded awful. Took her back to the shed. All wires are ok. Replaced points, condenser, plugs, coil. Tried re-adjusting the distibutor, but it doesn't help with the back-firing. Any ideas as to what has happened?

[Log in to Reply] [No Email]

ApexDeere

06-08-2007 02:57:33

Report to Moderator

Re: 40 not running right in reply to Apexdeere, 06-03-2007 05:56:37

Found some time to pull the valkve cover off last night. Bent pushrod and one pushrod that had jumped out from under the rocker. The only thing I can figure is that I had a valve(s) to stick? They are free now. I intend to pull the head again, and have the valve guides checked for the proper tolerances. Any other suggestions?

[Log in to Reply] [No Email]

40 headache

06-07-2007 20:06:43

Report to Moderator

Re: 40 not running right in reply to Apexdeere, 06-03-2007 05:56:37

sounds like what mine was doing, after pulling oil pump and try different thing with timming and point etc. I rebuit the carb. prior to this so I know that was good , so I thought , I tore it down again and found one of the holes in the bottom of bowl was plugd blew air through every thing again runs fine , good luck

[Log in to Reply] [No Email]

Johnnyputt

06-04-2007 04:06:29

Report to Moderator

Re: 40 not running right in reply to Apexdeere, 06-03-2007 05:56:37

I had one act the same way. Ran fine then all of a sudden she backfired like crazy and ran on one cylinder. Had a pushrod come out from under the rocker arm.

[Log in to Reply] [No Email]

Henry M

06-03-2007 15:19:04

Report to Moderator

Re: 40 not running right in reply to Apexdeere, 06-03-2007 05:56:37

Here is something I did on my 420 once, but at the time it would just shut down and then eventually restart until one day it stayed down. Believe it or not it turned out to be the ignition switch.

I was busy at the time and ran for a spell with a wire jumped from the hot lug on the starter to the side of the coil that the initial 6 volts goes into. Pretty fancy ignition switch.

Good luck, but my luck that is not your problem.

Another idea could be the spark jumping around. I would shoot a timing light in the timeing hole and do a little running up and down from idle to fast idle and watch the spark mark to see if it advances smoothly and most important that it stays steady when the rpm is steady.

When mine stuck a valve it just dropped a cylinder and ran on one.

[Log in to Reply] [No Email]

Henry M

06-03-2007 10:33:59

Report to Moderator

Re: 40 not running right in reply to Apexdeere, 06-03-2007 05:56:37

It would help to post back and let us know if it ran ok after it set all night or cooled down?

[Log in to Reply] [No Email]

apexdeere

06-03-2007 11:57:08

Report to Moderator

Re: 40 not running right in reply to Henry M, 06-03-2007 10:33:59

Sitting all night does not help. Whatever the problem, it doesn't appear to happen only when hot. I have cranked it several times since this first started (last Saturday). Still starts good but misses and back-fires like crazy. I hate to run it much until I can figure the problem out.

[Log in to Reply] [No Email]

CPeter

06-03-2007 10:30:22

Report to Moderator

Re: 40 not running right in reply to Apexdeere, 06-03-2007 05:56:37

Check fuel flow to the carb. Don't forget the screen in the inlet elbow.

CPeter

[Log in to Reply] [No Email]

apexdeere

06-03-2007 11:59:34

Report to Moderator

Re: 40 not running right in reply to CPeter, 06-03-2007 10:30:22

Fuel flow doesn't appear to be the problem. I have loosened the valve underthe carb and fuel flows freely.

[Log in to Reply] [No Email]

F-I-T

06-03-2007 08:43:22

Report to Moderator

Re: 40 not running right in reply to Apexdeere, 06-03-2007 05:56:37

Lots of possibilities...but since it ran pretty well until warmed up, sounds like it might have a sticky valve? Did you install new guides and maybe a new valve or two and the valve galled up and stuck after a warm up? Old varnish on the old valve stems can spall up and gum one open, too.

Check the compression. Don't jump to the carb yet, but do verify again your ignition has a good spark, and that the timing has not moved. Look at the advance plate for free action.

Frank

[Log in to Reply] [No Email]

apexdeere

06-03-2007 09:28:13

Report to Moderator

Re: 40 not running right in reply to F-I-T, 06-03-2007 08:43:22

I did replace the valves, guides, locks, etc. I have checked the spark again this morning and the spark is there. This afternoon I will try to go back out there and check the compression. A stuck valve did cross my mind, but since they are new and everything was replace, I thought it would be a long shot. No way, that I can see, that this engine could jump timing, since there is no timing belt nor chain.

[Log in to Reply] [No Email]

F-I-T

06-03-2007 09:44:14

Report to Moderator

Re: 40 not running right in reply to apexdeere, 06-03-2007 09:28:13

I meant more of a distributor that rotated in its clamp a bit, or an advnce plate sticking, not jumping timing. Jumping a tooth usually stops them.

New guides, not reamed correctly is a stuck valve waiting to happen. It might be loose this afternoon when its cold again, but with new guides and valve stems, it's more likely to hang up rather than less likely.

Frank

[Log in to Reply] [No Email]

[Options] [Printer Friendly] [Posting Help] [Return to Forum] [Log in to Reply]

TRACTOR PARTS	TRACTOR MANUALS

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