450 Problems Continue.....

[FarmallLovinGuy]

I looked in the fuel tank, and could not locate any floaters. Added some fuel, and replaced the new coil with the old one. Ran it down the road last night....ran fine. Went to plow this morning, and it ran fine for the first 5 minutes, then started to chug and spew black smoke (it's a gas). So I shut it off and felt the coil, quite hot. Started again after it cooled down, and same thing happened, leaving me to believe the coil is the problem, and the new coil didn't work because of the internal resistor. To get a new coil, how do I know if I need 6 or 12 volt, how can I tell on the old coil? I looked and didn't see any marks or anything. Thanks

 

[WellWorn]

If the coil has an external resistor (usually looks like a white porcelein block, about 7/8" square by about 4" long) located in the ignition switch side of the circuit, it has a 6 volt coil. If you have a meter, the resistor should read somewhere between 1.5 and 3 ohms. If the circuit does not have a resistor, make sure you get a 12v coil. Someone recently posted the NAPA part number on the Ford forum here. Also check the point gap. Running it too small results in the coil being "on" longer, which can add to heating, and worse spark.

 

[FarmallLovinGuy]

Well the coil has a resistor mounted
on it, but the resistor is not
hooked up. There is a wire attached
to the resistor, but was not
connected anywhere, leading me to
believe that there is a resistor
elsewhere. Is this a safe
assumption? Based on this, I would
need a 6 volt, correct?

 

[rustyfarmall]

(quoted from post at 12:04:20 06/04/17) Well the coil has a resistor mounted
on it, but the resistor is not
hooked up. There is a wire attached
to the resistor, but was not
connected anywhere, leading me to
believe that there is a resistor
elsewhere. Is this a safe
assumption? Based on this, I would
need a 6 volt, correct?

That tractor was originally 6 volt. There was no need for a resistor. The 12 volt conversion DOES require a resistor. Most likely the resistor you have located WAS installed at the time of the conversion. Just because it currently is not connected does not mean that it doesn't work. Connect the resistor as it is supposed to be and you will probably see an end to your troubles.

 

[FarmallLovinGuy]

I'm guessing so, but is this how it
needs to be wired? Does the resistor
need to be mounted a certain way, as
in does it have a positive and
negative sides? Thanks again.

 

[rustyfarmall]

(quoted from post at 12:32:11 06/04/17) I'm guessing so, but is this how it
needs to be wired? Does the resistor
need to be mounted a certain way, as
in does it have a positive and
negative sides? Thanks again.

Yes. That should work. As far as I know, the resistor has no positive or negative posts.

 

[old]

Coil DO NOT have internal resisters there just made either as a 6 volt coil or a true 12 volt coil simple as that.
That said a true 12 volt coil will say right on it NO external resister need or some such thing. A 12 volt coil that needs a resister will say on it resister needed or some such thing right on it if the coils are of any quality

 

[FarmallLovinGuy]

I went out and wired up the resistor
like in the diagram. Started right
up and ran well for about 5 to 7
minutes. Then the same crap started
happening again, with the surging
engine and the plumes of smoke.
Finally had to shut it down.....I'm
completely lost as to what it may be
and frustrated as everything. Again,
thanks for any help.

 

[JAsher452x]

i had a similar issue a few years ago with my 606. About drove me to drinking. With mine it ended up being the condenser, causing over saturation of the coil, leading to thermal break down of the coil.

 

[rustyfarmall]

(quoted from post at 13:49:53 06/04/17) I went out and wired up the resistor
like in the diagram. Started right
up and ran well for about 5 to 7
minutes. Then the same crap started
happening again, with the surging
engine and the plumes of smoke.
Finally had to shut it down.....I'm
completely lost as to what it may be
and frustrated as everything. Again,
thanks for any help.

Go to your favorite auto parts store and buy a new resistor. Also, do not automatically assume there is nothing wrong with the carburetor and fuel system.

 

[Janicholson]

A collapsing intake air hose could also do it. Good thinking. Jim

 

[John M]

When it starts puffing black smoke, turn the gas off and see if it clears up in a few seconds. Sounds to me like the float is hanging up.

 

[FarmallLovinGuy]

I don't know if it tells you anything, but the fuel filter, at times seems to not be as full of gas as it should be.

 

[ss55]

I could be any one or a combination of number of things:
A high or sticking float will run way too rich with black smoke.
A bad condenser can cause misfire/backfire in exhaust.
Too much voltage to the coil will also send too much current through the coil and points, that could overheat the coil after 10 to 30 minutes, and also burn the breaker points.

 

[FarmallLovinGuy]

What's the best way to diagnose a sticking float in the carb?

 

[John M]

Do what I told you to do. As the fuel in the bowl runs out, the engine will smooth out until the level gets low enough to eventually make the tractor cut off. (IF its a sticking float) The filter not filling up all the way doesn't bother me too much. But since you mentioned it, it is a filter that will for with a gravity flow system, isn't it?