Tractor Talk Discussion Board |
Re: Engine Backfires?
[ View Follow Ups ] [ Post Followup ] [ Return to Forum ]
Posted by Mike C. on April 01, 2002 at 09:04:49 from (64.17.237.124):
In Reply to: Engine Backfires? posted by Mark on March 31, 2002 at 09:01:33:
Assuming that the backfire happens after you turn the key off, you must be talking about afterfiring through the exhaust. Keep in mind that an engine is nothing more than an air pump and by turning off the ignition, you are only eliminating spark. The engine continues to spin pumping air/fuel mixture into the exhaust until the engine stops. This air fuel mixture is then ignited by heat from the exhaust system. Exhaust systems are heated up to high enough temperatures to ignite fuel by engine running either too rich or too lean. Too lean of a mixture will heat up the exhaust as well as burn valves. Too rich is less damaging on the engine but dumps raw fuel into the exhaust causing it to burn there creating the heat which causes the afterfire. A simple method for proper carb adjustment is known as "Propane enrichment method". All you need is a small propane torch and a tachometer. Remove the torch tip and attach a 1/4 in diameter hose about 2 ft long to the tube after you remove the torch head or tip. Start engine and allow to run to operating temp. At idle, allow propane to enter through air intake of carb and watch tachometer for an increase of 50 rpm. More than 50 rmp, engine is running too lean. Less than 50 rpm or if engine stumbles or stalls, engine is running too rich. This adjustment will set the Idle air/fuel ratio but will not compensate for an improper size main jet. After you make this adjustment, run engine under hard load for a while and shut down quickly then check plugs. Chocolate colored cone indicates correct air/fuel ratio for main jets. Black is too rich, white is too lean. If your not into changing jets, allow engine to idle for a short time allowing exhaust to cool first as pointed out by the other replies. best of luck...
Follow Ups:
Home
| Forums
Today's Featured Article -
New Hitches For Your Old Tractor - by Chris Pratt. For this article, we are going to make the irrational and unlikely assumption that you purchased an older tractor that is in tip top shape and needs no immediate repairs other than an oil change and a good bath. To the newcomer planning to restore the machine, this means you have everything you need for the moment (something to sit in the shop and just look at for awhile while you read the books). To the newcomer that wants to get out and use the machine for field work, you may have already hit a major roadblock. That is the dreaded "proprietary hitch". With the exception of the
... [Read Article]
Latest Ad:
Sell 1958 Hi-Altitude Massey Fergerson tractor, original condition. three point hitch pto engine, Runs well, photos available upon request
[More Ads]
Copyright © 1997-2024 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 HeadquartersWebsite Accessibility Policy |
|