Posted by KEB on October 18, 2007 at 21:17:40 from (72.19.170.5):
In Reply to: Ignition coil posted by Leckster on October 18, 2007 at 19:39:24:
Assuming the ignition switch is on, there will be current flowing through the coil whenever the points are closed. Engines normally stop with the points closed as one piston is coming up on a compression stroke. If the engine isn't running, its normal for the coil to get warm, but not so hot that you can't touch it.
Whether or not the coil case is grounded is immaterial. The return path for the high voltage pulse is through the condenser and the wire to the distributor. The ignition coil and condensor form a resonant circuit which results in a higher voltage spark than just a simple coil. There is no electrical connection to the case of the coil.
First thing I would do is replace both the points & condensor. Its a cheap way to eliminate a couple potential problems. A bad condensor will cause a weak spark, since the circuit is no longer resonant. Look carefully at the points, the contacts should be smooth. If there's a mound of metal on one contact and a corresponding crater on the other, the condensor is either bad or the wrong value. If both contacts are black and pitted, there's too much current flowing through the points, probably because you're using a 6 volt coil on a 12 volt system without a ballast resistor.
By the way, never clean ignition points with sandpaper. It'll leave abrasive particles embedded in the contact surfaces & cause early point failure. If you can't find an actuall point file, a metal nail file will work. If you have to file points, they're on their last legs anyway & you might as well replace them.
As John T noted, if you have a 12 volt system you either need a coil that's marked for 12 volts or a ballast resitor between the ignition switch and the + side of the coil. If its a 6 volt system, you do not need a ballast resistor, and should make sure you use a 6 volt coil.
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 ]
Today's Featured Article - Tractor Hydraulics - The Basics - by Curtis Von Fange. Hydraulics was one of the greatest inventions for helping man compound the work he can do. It’s amazing how a little floor jack can lift tons and tons of weight with just the flick of a handle. What’s even more amazing is that all the principals of hydraulic theory can be wrapped up in such a small package. This same package applies to any hydraulic system from the largest bulldozer to the oldest and smallest tractor. This short series will take a look at the basic layout of a simple hydraul
... [Read Article]
Latest Ad:
Oliver 550 Diesel runs like a watch three point hitch pto engine gone threw about two hundred hours ago nice clean tractor
[More Ads]
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.
