Yesterday's Tractor Co.
Shop Now View Cart
   Allis Chalmers Case Farmall IH Ford 9N,2N,8N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   Traditional YT Forum ViewClassic View   RegisterRegister 
 ProfileProfile    Log inLog in 

H Backfire Problem


 
Post new topic    
View previous topic :: View next topic  
Author Message
Doug Kieta
Regular


Joined: 15 Feb 2012
Posts: 49


Report to Moderator

PostPosted: Sun Mar 11, 2018 2:00 pm    Post subject: H Backfire Problem Reply to specific post Reply with quote

Lately, when I shut my 1951 H engine off with the kill switch I get a very strong backfire. What is the likely cause of this? This tractor has been running very well for a long time, so I don't understand what could have changed to suddenly cause this repetitive problem. Any tip you guys can offer that may help me solve this problem will be most appreciated.
 
Back to top
View user's profile
old
Tractor Guru


Joined: 12 Mar 2000
Posts: 77988
Location: Lake of the Ozarks area of MO

Report to Moderator

PostPosted: Sun Mar 11, 2018 3:01 pm    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote

Hot spots or carbon build up and cause that or you do not idle it down and let it cool for a bit before you shut it off. Best way to stop it and be sure it is not going to do it any more is shut the gas off and let it run till it dies and the back fire will not happen. One the ignition is turned off the engine still spins over for a few more turns which pumps raw gas into the cylinder and then out into the manifold where they hit hot carbon so you get a big bank
 
Back to top
View user's profile
Bob M
Tractor Guru


Joined: 28 Dec 1997
Posts: 7842
Location: Chili, NY

Report to Moderator

PostPosted: Sun Mar 11, 2018 3:50 pm    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote

Old's advice is right on!

Set the idle as slow as it will go (450 - 500 RPM max).

Then when you are done with the tractor, let it slow idle a minute or two before hitting the kill switch. It will shut down quietly.

Or do as I do - shut off the fuel at the sediment bulb and let it run until it quits. Don't forget to turn off the ignition after it stops!
 
Back to top
View user's profile
DR. EVIL
Long Time User


Joined: 26 Aug 2014
Posts: 1287


Report to Moderator

PostPosted: Mon Mar 12, 2018 4:35 am    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote

If you are running the tractor hard, let it cool down 5 FIVE minutes at 700-1000 rpm, then idle down to 450-500 rpm and push ignition button in.

You may have a leak in the exhaust manifold letting raw air loaded with oxygen into the manifold & muffler. Might have been caused by the pressure of the backfires.

Dad's Super M-TA used to backfire like that, also diesel backwards if shut off too hot. Let it idle 3-5 minutes and no problem.
 
Back to top
View user's profile
BarnyardEngineering
Tractor Guru


Joined: 23 Mar 2016
Posts: 3935


Report to Moderator

PostPosted: Mon Mar 12, 2018 6:29 am    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote

If you are not running the tractor hard, then something else is causing it to heat up excessively. Running lean, timing being too advanced or retarded, can cause the engine to run much hotter than normal even under light loads.

Also tractors need regular maintenance. A tractor can run well for a long time, but if you do not perform all the regular maintenance you can only expect that suddenly without warning the tractor will start running differently than you expect.
 
Back to top
View user's profile
OldFarmall450
Long Time User


Joined: 21 Apr 2016
Posts: 512
Location: Wichita Falls, Texas by Gawd!!

Report to Moderator

PostPosted: Mon Mar 12, 2018 6:31 am    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote


If I've been working my 450 and forget to let her cool down before killing her for lunch she will diesel and pop some. Plowing with a Super M as a kid my boss told me to always let her cool down a few minutes before turning the key, but sometimes I'd forget and I can still see him shaking his head.

At the end of the day I'll turn off the gas and let her slowly stop on her own.
I hope this helps.
 
Back to top
View user's profile
Pete in Holland MI
Regular


Joined: 17 Oct 2014
Posts: 172


Report to Moderator

PostPosted: Mon Mar 12, 2018 1:39 pm    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote

With a carburated engine, when you turn the engine off, you are only turning the spark off. As the engine slows down & stops, it's sucking in gas into the system. Hot carbon in the cylinder can trigger the explosion.

As others have mentioned, always let a hard working engine......of any kind (tractor, lawn mower, pressure washer, car)........cool off a bit at idle before shutting it off.

Your car does that pretty much automatically as you slow down from the road and slowly drive up the drive to the house.

Pete
 
Back to top
View user's profile
rustred
Tractor Guru


Joined: 01 Jul 2009
Posts: 6904


Report to Moderator

PostPosted: Tue Mar 13, 2018 7:43 am    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote

the thing is ... you need the idle adjusted as slow as it will chug. less than 400 rpm. if that dont work then put throttle in idle position and backout idle screw on carb till engine stops on its own. this guarantee's that the throttle butterfly is completely closed,as thats what you want to prevent fuel being sucked into the intake. then when using tractor and idling it for a bit just close throttle and hit kill switch and it will stop. a very easy fix that only reqires a screwdriver!
 
Back to top
View user's profile
fixerupper
Tractor Guru


Joined: 12 Oct 2003
Posts: 15847
Location: Albert City Iowa

Report to Moderator

PostPosted: Tue Mar 13, 2018 7:47 pm    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote

The last military vehicle restoration I did had a 817 cu in Waukesha gasser with two big one bbl carbs. To shut it down you pull a knob that kills the ignition but it also opens a valve in the intake manifold that lets in air so it doesn’t have enough vacuum to draw through the carbs and can’t diesel. It won’t help your tractor but it’s an interesting concept.
 
Back to top
View user's profile
fixerupper
Tractor Guru


Joined: 12 Oct 2003
Posts: 15847
Location: Albert City Iowa

Report to Moderator

PostPosted: Tue Mar 13, 2018 7:53 pm    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote

I hope this comes out clear enough to read.
 
Back to top
View user's profile
caterpillar guy
Tractor Guru


Joined: 24 Jun 2007
Posts: 3538


Report to Moderator

PostPosted: Sat Mar 17, 2018 5:30 pm    Post subject: Re: H Backfire Problem Reply to specific post Reply with quote

Could also need the valves adjusted if they are not shutting completely can cause that problem. As well as all the other things listed.
 
Back to top
View user's profile
Display posts from previous:   
Post new topic    Yesterday's Tractors Forum Index -> Farmall & International Harvester (IHC) All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  

TRACTOR PARTS TRACTOR MANUALS
Fast Shipping!  Most of our stocked parts ship within 24 hours (M-Th). Expedited shipping available, just call! Most prices for parts and manuals are below our competitors. Compare our super low shipping rates! We have the parts you need to repair your tractor. We are a company you can trust and have generous return policies. Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ About Us ]

YT Home  |  Forums

Modern View Forum powered by phpBB © 2001, 2005 phpBB Group

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