farmall 300 dies when hot

Anonymous-0 · Jan 13, 2010

I all, have a farmall 300 converted to 12v that when i run it awhile and it warms up it stops running. can't get it running again till it cools down. thinking a fuel issue but not sure. any advice helps.
thanks

D7fever · Jan 13, 2010

Do you have a resistor inline for your coil? if not, it is your coil. Either put a 12 volt coil on or put in a ballast resistor. Or could be just a bad coil. If you are getting some backfire before it stops, it is probably your condenser.
Good luck

Anonymous-0 · Jan 13, 2010

now that you mention that it does backfire. it's got a 12v coil on it now, but no resistor. do i need one with a 12v coil?

Bob M · Jan 13, 2010

You won't need a ballast resistor with a true "12 volt" coil.

Suggest you check the spark when the engine is cold. (Pull the wire from the center tower on the disributor, hold it a half inch or so away from the block and crank the engine). You should get a sharp, blue spark.

Then check it again after the engine has warmed up and quit on you.

If now you get only short, lazy yellow spark (or no spark at all...) look for a bad coil or condenser.

But also check the breaker point gap! If the gap's too close (ie. only a few thousanths) it can cause the same symptoms.

Bob M · Jan 13, 2010

You won't need a ballast resistor with a true "12 volt" coil.

Suggest you check the spark when the engine is cold. (Pull the wire from the center tower on the disributor, hold it a half inch or so away from the block and crank the engine). You should get a sharp, blue spark.

Then check it again after the engine has warmed up and quit on you.

If now you get only short, lazy yellow spark (or no spark at all...) look for a bad coil or condenser.

But also check the breaker point gap! If the gap's too close (ie. only a few thousanths) it can cause the same symptoms.

old · Jan 13, 2010

Do this and then let us know what you find. Start it up and use it till it dies. When the dies jump off and check for spark ASAP if you have no spark or it is real weak most likely your coil is bad. Also fell the coil, be careful because if it is going bad it could be very hot. I'll almost bet you will find little or no spark and that means your coil is bad and you need to buy a TRUE 12 volt coil. A true 12 volt coil will say right on it no resister needs or something to that effect

Anonymous-0 · Jan 13, 2010

thanks for the replys. i will check this stuff out and post back.

stan jefferies · Jan 13, 2010

I have no advice but this makes me wonder. Twice this summer after being run for about 2 hours my 400 acts up when I throttle down. If I run it 3/4 throttle for 2-3 hours, when I throttle all the way back it acts like its running out of gas and it has to be kept running fast. What do you think?

Bob M · Jan 13, 2010

Sounds like the idle fuel mix goes lean on long runs. When it happens again try gradually pulling the choke while throttling down. If you find a partial choke setting where it will slow idle OK a lean mixture is the problem.

---

Possible causes:

1 - Carb idle mix set too lean. Turn the mixture screw IN 1/4 turn at a time to make it richer.

2 - Loose gasket opening up when the engine gets hot allowing a vacuum leak. Check the carb-to-manifold and manifold-to-head gaskets for leaks and the studs & nuts tightness.

2 - Crud floating around in the carb getting sucked into and plugging the idle fuel circuit on long runs. Need to disassemble and thoroughly clean the carb and fuel inlet screen!

Good luck!

farmall 300 dies when hot

Anonymous-0

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D7fever

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Anonymous-0

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Bob M

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Bob M

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old

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Anonymous-0

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stan jefferies

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Bob M

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