Re: Re: Spark Plug Voodoo

Posted by Mark on February 15, 2004 at 05:44:52 from (209.151.115.251):

In Reply to: Re: Spark Plug Voodoo posted by Nebraska Cowman on February 14, 2004 at 17:14:58:

Right on target brother.

The coil is a magnetic device and it's basic philosophy is that it is going to generate whatever voltage it has to to keep current flowing...current is what you see when you pull the plug wire and see the spark....and current is what was running into it from the battery during the time that the contacts were closed.

Apparently, as mentioned by Doug in OR, the insulator is "leaking" (a term for being a semiconductor rather than a pure insulator). As a result, as the points open and the energy (that was stored in the coil when they were closed) starts releasing, it attempts to do what I said in paragraph 1. With a leaking insulator, the coil doesn't have to get to very much voltage to push out the energy stored in it (current flow) and essentially bleads off at low voltage.

However, when you pull the plug wire and initiate a "jump", there is no leakage there (thin air) and the coil can do it's thing per para 1 and get to a good 18,000 volts and put out a smack...thus the plug fires even though the insulator is still "leaking". Additionally, when you jump a plug with the wire, you'll get a good smack...really bigger that what occurs in the combustion chamber as your gap is .100 to .200 inches or thereabouts, while the plug has been set to .030 thereabouts. Bigger the gap, the more voltage the coil has to generate to "attempt to keep current (in the coil) flowing".

I have read posts herein and thoroughly believe that you should either install new plugs when you suspect a problem or give the insulators a very good sandblasting. Your combuston chamber acts like a KILN, used to bake ceramics, and it bakes combuston by products to the insulator and eventually there is enough crud to conduct electricity. Just spraying them with chemical cleaner won't remove it.

Mark

Follow Ups:

• Re: Re: Re: Spark Plug Voodoo Seifdoggy2 19:54:40 02/17/04 (0)

Post A Followup Name: E-Mail: Subject: Re: Re: Re: Spark Plug Voodoo Comments: Optional Link URL: Link Title: Optional Image URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

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 ]