Ford 640 Sputtering Out

pobox1589

New User
Appreciate the help from when my electronic ignition went out; got a new challenge since hay season started.

I use my 1956 Ford 640 to do some of the smaller tasks in our hay operations, like tedding and raking. It does great usually for about 2 or 3 hours, maybe a little longer, then it starts sputtering and dies
on me. Has more than plenty of fuel. It'll start back up, but usually dies back off once it gets under load. If I let it sit for a few hours, it'll start back up, but usually does the same thing before
too long. If I let it sit overnight, it'll do great the next day, but only for 3 or 4 hours.

It sounds like it's getting too hot, but the coolant is full and the fan belt was just replaced. I figure it's one of two things:

- While the coolant is full, it's not circulating right - may need to flush the coolant system and replace the water pump
- I had "heard," that if the hot wire running to the ignition coil gets too hot, it'll start shorting out if it's too close to the engine block. Not sure if that's it, but would insulating that with
electric tape fix the problem?

That's just what I gather it, "could," be, but I'm looking forward to hearing what you all say. Thanks for all the help, I appreciate it.
 
I had mine do that and it was the coil going out. It would die when it got to hot let it cool off and fire right back up. I'd try a new one.
 
Really. I had thought it might be that about the coil, had seen something like that on another site, but I?ve had this happen on the past few coils I?ve had on this tractor. Is it the coil getting worn out due to excessive use or because it?s gettin too hot? Is it getting too hot from inside the coil or is it heat from the engine? Sorrry for all the questions, just trying to learn as much as I can.
 
I had a similar problem a few years ago. I decided that my coil was bad, so thought I would replace it. I started to disconnect the hot wire to the coil----and the wire broke before I got it off. The wire must have been badly corroded or frayed under the insulation. I replaced the wire and it has been working fine for several years.
 
Wow, ok. That would be easy to do, I?ll try that ext time the weather takes a turn on me and lets
me work inside.
 

Classic coil going bad. They just normally get hot while in use. Hot weather compounds the heat. When heating there is a little internal expansion which will allow a bad point in the winding insulation finally allow contact with another point, and ignition stops until it cools down. When it happened to my 1961 it took around two hours running before it would quit. Before getting a new one though, check for spark immediately after it quits.
 
Has it been converted to 12 Volt? If is has are you running a resistor on the wire going to the coil from the switch? I have ran in to two different tractors of mine with running problems that had been converted to 12 volt with no resistor by previous owners. One had a coil on it that clearly said no external resistor required but I put one on anyway and both run perfect now.
 
Right when it quits, check to see if you still have spark.
While it sounds like a classic case of a bad coil, why throw
parts at it when you haven't verified that it has lost spark?
If no spark, does it still have power to the coil?
 

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