[AT] Coil test?

[Dean VP]

Ralph:

A coil is very low DC resistance and an inexpensive multi-meter won't read
low resistance very accurately. I don't recall the DC resistance of a 6 or
12V coil at the moment but I would suspect it to be less than 2 ohms or so.
Maybe even 1.2 ohms. MY fuzz in the head won't clear this morning. A DC
resistance check at best can tell you whether the coil is open but you need
a really good meter to determine if a coil or two has shorted out. In my
limited experience a coil that goes bad is due to a high voltage insulation
breakdown due to heat and you won't be able to check that with a DC Ohm
meter. The only way to diagnose that would be to replace it with a known
good coil.

However, it seems to me to be a real stretch, with the symptoms you have
described, for it to be a coil problem. IMHO there are higher probability
areas that s/b pursued first. With what you have described so far I would
"bet the farm" on a fuel line, tank outlet, sediment bowl screen or
carburetor inlet screen blockage. 

Then there is one other possibility, Ice or water in the gas. After running
for awhile maybe the ice is melting. But I would think you would have real
problems starting up if there was gas in water in the tank as that settles
to the bottom and would freeze at the bottom of the tank, sediment bowl and
fuel lines. Maybe a can of "Heat" is in order if you think this is a
possibility. Particles of ice could cause partial fuel blockage but I would
think that would go away after running the tractor for a long time.

But every time I have had the symptoms you describe it has been a partial
fuel system blockage somewhere. 

Good Luck and tell us what you eventually find.   

Dean A. Van Peursem
Snohomish, WA 98290

I'm a walking storeroom of facts..... I've just lost the key to the
storeroom door 


www.deerelegacy.com

http://members.cox.net/classicweb/email.htm



-----Original Message-----
From: at-bounces at lists.antique-tractor.com
[mailto:at-bounces at lists.antique-tractor.com] On Behalf Of Ralph Goff
Sent: Sunday, January 09, 2005 10:21 AM
To: Antique tractor email discussion group
Subject: [AT] Coil test?

Another possibility that came up in a recent discussion of my Cockshutt 40
and its apparent fuel starvation problem. A friend had a JD 2010 that had
the same symptoms as my 40. The problem turned out to be the coil. After he
replaced it the tractor worked fine. Yet it exhibited all the symptoms of
fuel starvation under load. Pulling the choke would keep it running. Who
would ever have thought that was a coil problem?
Now I am wondering , is there any way I can test my six volt  coil  using a
simple $10 multitester. This tester will handle AC, DC voltage as well as
ohms.
Other than that I will have to "borrow" a good coil from somewhere to see if
it cures the problem on my 40.

Ralph in Sask.
http://lgoff.sasktelwebsite.net/


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