Ignition? Or? 641

Hey guys, I've got an intermittent..."thing"(?) going on with my 641 that I've been unable to pinpoint.
The majority of the time my 641 runs great-hot or cold, but occasionally it develops a rough running situation (backfires, wants to stall etc) for only a couple seconds and then returns to running great again (as if nothing happened). Sometimes it'll do it, (or not) once an hour or it'll do it once every third time I use the tractor etc (there's no rhymn or reason when it's going to happen or not). I'm stumped, I've checked everything I can think of, anyone have an idea?
I'm not sure if its related(?) but my ignition switch seems to be acting up as well, occasionally (not always) ill turn the key "on" take the tractor out of gear and hit the push button starter and NOTHING happens, and I mean nothing, complete dead stick, no sounds of any kind. But if I turn the key "off/on" etc and eventually I can push the start button and she'll crank and fire. I bought a replacent switch and I'm going to install it anyway but I wasn't sure if they were related (?).
Thanks
 
Well first off if it is wired as it was from the factory the ignition switch and the starter circuit are 2 different circuits and the starter will spin over with or with out it being one so did some one rewire it or what. As for the running problem what happens if you choke it when it does that?? Sounds more like a bit of dirt or rust in the carb then an ignition problem.
I would try the choke to see if that helps or hurts and also pull the carb drain plug and let gas flow for a few minutes. Catch the gas so as to look at it for water dirt etc.
As for the starter problem sounds like the safety switch maybe going bad
 
That's incorrect information for a 641.
The 4 post starter relay used on all of the X01 series tractors MUST have the key turned ON for the starter relay to work. I know that the X00 and previous Ford tractors did not need the key ON for the starter relay to work but Ford changed that with the X01 tractors.
Early Bronco: Yes your key switch is most likely the cause of your problems.
 

Thanks Texas!,
I was putting off installing the switch till later this week as I'm currently using the tractor (everyday in the pasture) but I think I'll install it first thing tomm morning, before i use it, now.
 
Yes, just because someone warms a chair at a keyboard and has 50,000 posts, doesn't mean that there is any knowledgeable content!!!
 
(quoted from post at 07:01:11 03/19/13) Yes, just because someone warms a chair at a keyboard and has 50,000 posts, doesn't mean that there is any knowledgeable content!!!

Well Ed, I wasn't discounting Old's post, however, considering my 601 (641) HAS to have the key "ON" to engage the starting/ignition system and I'm taking this from my experience and not from Texas!' Post.
So, in THIS case Old's post served to confuse me rather than solve the issue/answer my question.
Now, with that said, Old's posts have always helped me out on NUMEROUS occasions and he IS very knowledgeable on these Fords and I don't see him get very many wrong, I'd say he's about 99.9999% correct on these ford tractors. But I also know that Old can speak for himself, so ill shut-up.
 
On this I can only go by what I have seen and when we got the 841 we have it did in fact spin over with or with out the key on but you never know what some one else has done to one over the years
 
Ya and a comment like yours does knowing good for the forums. At least I try to help you on the other hand are only showing how bad a person you are and how you can make things bad on the forums
 
(quoted from post at 08:49:08 03/19/13) Ya and a comment like yours does knowing good for the forums. At least I try to help you on the other hand are only showing how bad a person you are and how you can make things bad on the forums

Old,
I never said anything negative in any way, shape or form.
 
My 861 will turn over without the key on. It won't start, but the engine turns over. As far as I know, it hasn't ever been modified. It has a 12vt system.
 
Guess you and I have odd tractors then from what the other guy said. Back when we first got this 841 it would spin over with or with out the key on but it has been since wired so that you no longer use the safety transmission start button
 

My orig 641, 6volt still has the orig key and switch but it won't do anything (not even crank) with the key off.
Which brings me to a question, on tractors that the key/switch doesn't do anything, how do you turn the tractor off? (I'm just curious)
I know my JD 3010 has a pull knob to turn the tractor off/kill it.
 
(quoted from post at 12:56:54 03/19/13) Guess you and I have odd tractors then from what the other guy said. Back when we first got this 841 it would spin over with or with out the key on but it has been since wired so that you no longer use the safety transmission start button
Nothing necessarily "odd" about those....just had 50 years of "tom, dick, & harry" messing with them. After many hands & 50 years, 'original' is hard to find! :wink:
 
On the ones that are set up with a key switch and the starter button that works with or with out the key turned on the 2 circuits are independent of each other. The key does in fact turn the ignition on and off but does nothing to the starter circuit
 
Yep hear you on that one. This 841 I have has a starter button on the transmission that has not worked in years and it was a ford dealer who unhooked it and set up a starter button right above the key switch so yep even a dealer can mess one up real good
 
If it"s gas powered and 12V it"s been modified.

All of the X01 series tractors (gas & diesel) had a 4 post starter relay. One big post connects to the battery (it doesn"t matter which one) and the other connects to the starter. One small post (again it doesn"t matter which one) connects to the side of the junction block that is "hot" only when the key is ON and the other one connects to the starter button on the transmission for the ground. If the key is ON and you push the starter button the coil inside the relay (solenoid) energizes and pulls the contactor across the two big posts sending power to the starter. If the key is turned OFF pushing the starter button does nothing because there is no power to the coil inside the relay (solenoid).
 

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