[Farmall] Hard starting F12

[Robert L. Holtzer]

Good thoughts, Karl!!

Bob H

At 10:30 AM 2/19/2005 -0800, you wrote:
>As other knowledgable F-12 fans have noted, the F-12 is not quite as 
>simple as you'd expect.  And every system has to be performing well in 
>order for the tractor to hand start.
>
>All you can do is go through them one at a time, systematically.
>
>Carburetor:
>Pretty much the same as any other carb, except for one item.  There's an 
>1/8" tube that runs from the lower portion of the carb up into the upper, 
>and it has a tiny orifice in its tip.  This tube tends to stick to the 
>upper part of the carb and get broken off.  I can't recall if Rice has a 
>replacement or not.
>
>Fuel Pump:
>Virtually always needs rebuilding.  Rice can supply a kit.  Critical to 
>the starting of your tractor, since it is needed to lift the fuel up to 
>the carb.
>
>Magneto:
>The impulse MUST be working, or the engine won't start.  You should hear a 
>loud click or clank each time you turn the starting crank.  A penetrating 
>oil will often free up the impulse, but don't use WD-40; it turns gummy 
>over time.  If the engine revs freely when you bump the throttle up, the 
>timing is probably set about right.  If the engine seems to 'labor', the 
>timing is retarded.  The timing called out in the I&T manual is too far 
>retarded for use with modern gasoline.
>
>Valves:
>0.013" gap between rocker arm and valve, same as the gap for the magneto 
>points.
>
>As Robert mentioned, the F-12 engine starts out with pretty low 
>compression, and you can't afford to waste any of it through leaky valves 
>or rings.
>
>There's a straight slot screw in the side of the carb which gives access 
>to the venturi.  On difficult to start F-12s, I squirt Wal Mart $0.79 
>carburetor cleaner in through that screw hole.  Burns like gasoline, won't 
>destroy an engine like ether (starting fluid) will.
>
>Good luck!
>
>-Karl
>
>
>
>>I just bought a F12 & do not know much about them. I have a hard time 
>>starting it. It runs good once it starts. I don't know if it's me or the 
>>tractor needs a little tuning. I have heard some people say theres will 
>>start on the first few pulls, is this true? What is the best service 
>>manual for me to buy? Thanks for any help!
>>
>>Kevin Hood
>
>
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