[Farmall] Farmall 340 Not starting

[Bigdog]

Larry -
    Yes, but only if the points are actually making and breaking to generate 
the pulsed direct current in the primary side of the coil.  You need to 
separate your thinking on the coil and consider both halves separately.  The 
primary circuit on the coil must be functioning properly in order to 
generate a voltage in the secondary.
    Can you try this test? - there is a wire running from the + terminal on 
the coil down to the distributor. (this connects to the points inside the 
distributor).  Remove this wire from the coil and connect a jumper wire to 
the coil long enough to reach a good grounding spot.  Turn the switch on and 
with the coil output lead removed from the distributor cap and placed close 
to ground, quickly touch the jumper wire to ground for a brief moment and 
then remove it from ground.  Each time you touch ground, it should fire the 
coil and you should see a spark.
    If this produces a spark, your problem is in the distributor / points 
area.  If there is no spark, you have a problem with voltage supply to the 
coil or the coil itself.
    My inclination is to think that when you replaced the points and 
condensor you may have inadvertantly grounded a wire or the points 
themselves have glazed over from setting on a shelf somewhere and are not 
conducting.  The other possibility is the condensor could be shorted. 
Condensors rarely fail and are either good or bad - there is no in between 
with them.
    I should ask, do you have a voltmeter or multimeter?  I can guide you 
through some checks.

BD
----- Original Message ----- 
From: Larry Hardesty
To: 'Farmall/IHC mailing list'
Sent: Wednesday, July 26, 2006 12:11 PM
Subject: RE: [Farmall] Farmall 340 Not starting


Bigdog.  Should I not get a spark when I take the main wire running from
the coil to the distributor and put the distributor end near a ground, such
as frame of the tractor or the + wire on the side of the distributor and
then crank the tractor?  I am not.   So it would appear no voltage is
running from the coil to the distributor.  Don't know why or the remedy...or
am I doing some faulty thinking.

Larry

-----Original Message-----
From: farmall-bounces at lists.antique-tractor.com
[mailto:farmall-bounces at lists.antique-tractor.com] On Behalf Of Bigdog
Sent: Wednesday, July 26, 2006 9:59 AM
To: Farmall/IHC mailing list
Subject: Re: [Farmall] Farmall 340 Not starting

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

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