Farmall A won t start

[internationalB250]

So I bought a little Farmall A to tinker with and tinkering is all I ve done
Wouldn t start and had no spark so I replaced all the inside of the mag, rebuilt carb and made sure everything was on time as per forums and videos and still can t get it to go.
It ll fire at idle speed but will not at any other throttle or choke position. Towing it, it will fart and sputter sometimes and sometimes not. Some days it will start and idle but won t throttle up and other days it won t do a thing. I m just not sure what to think anymore.

Any thoughts? Thanks Jamie

 

[Janicholson]

Firing order 1342 from front to back of engine. Look at rotoe rotation and make sure you are wired correctly. Set the
impulse coupling on the mag so it trips just at TDC. Make sure the mag rotor drive gears are timed (marks on teeth) so it
points to the correct tower terminal just after clicking. Jim

 

[internationalB250]

Thanks for the reply!
All is timed properly, time on TDC, gears in mag lines up perfectly, mag trips just just before TDC on 1 and the rotor points directly to fit on 1 when it trips...... mind boggling

 

[DaveBN]

Call me 231-557-3163. Too much to type. I have several ideas and you
sound frustrated.

Dave.

 

[used red MN]

You have to determine if it is indeed losing its spark. Take a known good spark plug like one out of your lawn
mower etc. ground it to the frame and put one of the spark plug wires from a cylinder on it. If you have a helper
you can have them watch the spark while you a trying to start or run it. Now if it was a coil ignition I would almost
bet you would find it is not the spark but fuel. However I have very little experience with mag equipped tractors.
In general on this forum folks like to foo-foo starting fluid but on a gas engine it is next to harmless. So have you
tried spraying starting fluid in the carb while cranking? One thing that is sort of a long shot but is the Venturi in
the carb? See link number 5, either brand of carb that could have been installed on your tractor would have this,
and in some cases it can be installed upside down.
Farmall A carb

 

[internationalB250]

Has good spark, and new spark plugs. Tried starter fluid to no benefit at all. The Venturi is in correctly, thanks for the diagram though. Talked to a few people and I think we may have found the problem.
Will keep you posted when I get into it and see.
Fingers crossed
Thanks, Jamie

 

[Steve@Advance]

A good quick test of the engine condition in general, ground the mag, hold your hand tightly over the carb intake, crank the engine through.

You should get a strong vacuum and hand wet with gas.

If little vacuum, there is a vacuum leak or valve problem.

If good vacuum and no gas, there is a fuel problem.

Look at the points, be sure they have enough spring tension to snap shut when released. Possibly they are failing to close above idle speed.

Also try loosening or removing the exhaust. A clogged exhaust will sometimes idle but not rev up.

 

[fixerupper]

There is spark and then there is good spark. First thing to come to my mind is weak spark caused by a weak condenser. A new condenser can be bad out of the box. A good hot spark should snap a 1/4" gap. Stick a phillips or small slotted screwdriver in a spark plug boot, hold the shank of the screwdriver close to metal, crank it over and see what happens.