[Farmall] Farmall 340 Not starting

Bigdog dbigdog at columbus.rr.com
Wed Jul 26 07:58:37 PDT 2006


Larry,
    Some of your description is not clear to me so pardon me if I repeat 
what has been said.  The current path for the ignition system would run from 
the battery (ignition switch) to the coil (-) terminal (if it is a positive 
ground system), then through the coil primary winding to the (+) terminal 
then through a wire to the distributor side post where it would pass through 
the points to ground.  As the points open and close it creates a momentary 
or pulsating current flow through the coil primary winding which generates a 
high voltage in the secondary of the coil.
    Thus, per George's description, if you open and close the points with a 
screwdriver you will replicate the action of the lobes on the distributor 
and it should produce a spark at the secondary.  It is important to remember 
that the spark is generated during the building and collapse of the 
electro-magnetic field in the primary so the pulsating current is necessary 
to generate a spark.
    If I interpret your descriptions correctly, it sounds like the coil is 
intact.  You must verify that the points are opening and closing to generate 
the spark.  Also, the condensor is in parallel with the points and a shorted 
condensor will negate the opening of the points.
    I have been quite busy lately and have not kept up with this thread 
totally so I'm not fully aware of what you have and have not done but I see 
that you did replace the points and condensor.  It is not unusual to find 
new points glazed over right out of the package so I would burnish them to 
assure contact.
    I would crank it over with the distributor cap off to verify opening and 
closing of the points, then make sure the points are clean and not burned. 
Perform George's test by using the screwdriver to open the points and 
checking for spark at that point.


----- Original Message ----- 
From: Larry Hardesty
To: 'Farmall/IHC mailing list'
Sent: Wednesday, July 26, 2006 10:34 AM
Subject: RE: [Farmall] Farmall 340 Not starting


George,  I put a new coil on.  However, no spark to the points.  I took the
wire off from the coil to the distributor and flashed it to ground.  No
spark.  I checked and run a wire from the negative to positive side of input
to the coil and got a spark.  So I have spark going into the coil.  Now it
is a new coil.

Also, I connected battery cables from the battery to the positive and
negative side of the coil and got some spark.  So some voltage going through
the coil, but I would say not much.  I did this with the coil I took off and
got the same.

Can a new coil be bad; or would there be something happening to make a new
coil go bad?  Got me baffled

Thanks for the help.

Larry

/farmall 




More information about the AT mailing list