B Farmall running problems

[TedinNE]

A couple things I have run into over the years. Had an A that had set several years. Every thing checked ok new parts did no good. Would run just enought to keep it interesting. some one had put a rag in the intake manifold. H would start hard and not run. New points had the rubbing block on backwards. Just a thought.

The venturi can be put inupside down on some carbs.


















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[560Dennis]

A couple things I have run into over the years. Had an A that had set several years. Every thing checked ok new parts did no good. Would run just enought to keep it interesting. some one had put a rag in the intake manifold. H would start hard and not run. New points had the rubbing block on backwards. Just a thought.




















a

interesting findings ,thanks for sharing.

 

[Janicholson]

All I know is we use them with no ceramic resistor,all our 12 volt farmalls fire up within a second. .......and we have 3 that are still 6 volt 2 have magnetos,1 has a distributor, they also fire right up. Personal opinion,it's all in the details. The tune up ,the adjustments. Too many folks swap to 12 volt , electronic ignition, new carb, and wonder why new parts didn't help. . Simple troubleshooting and tune up usually solves the problem.

I just try to be accurate in describing components. There were some Ford (early) 6v coils with actual resistors in them. but they are just made with smaller wire and more of it. Jim

 

[Pete in Holland MI]

With a Ford Jubilee, I converted to 12v and went to NAPA and the guys gave me a 12 v coil "no resistor required", (product number 905). Tractor fired up and has run flawlessly for years. Bought a Cub that had been converted to 12v, but the coil was still 6v, with a resistor in the circuit. One day, it didn't want to start. Diagnosis showed the resistor had failed. Bought the same coil I put in the Jubilee and elimated the resistor from the system. Tractor starts and runs flawlessly. Resistors are incorporated into systems for those who don't want to put out the money for a new coil.

 

[flatheadvff]

I think I still haven't clarified a couple of things. So I will try...This is not a tractor that has been sitting for years, just over the winter. Owner uses it to mow his yard, approximately 10 acres I believe, plus other small jobs. No, I am not running a 6 volt coil and expecting a resistor to convert to 12 volt. I am running a 12 volt external resistor coil. Grew up in family parts store, automotive machine shop, and the family farm. All the paper catalogs that we used in the parts business, before the disorganized computer catalogs with missing information took over, listed coils as external or internal resisted coil. Whether the resistance comes from a resistor or from how it is wound is not the point. If you have an unmarked coil, how do you determine which kind it is? You use an ohmmeter to test the resistance. An internal resistance coil will have more resistance. Now between my dad and I, we have at least a dozen distributor tractors, Most poppin johnnys, some masseys, allis, and International. Now a couple are still 6volt (the play toys), but most are converted to 12v and alternators. We farmed with these tractors, and still use them, even though we've upgraded to larger diesel tractors when we took over grandpa's farm. While farming, conditions aren't always perfect, cold weather, rainy weather, maybe the first start after winter storage, not brand new parts as they are only new when installed, low battery etc. So sometimes you need that extra help to get started. An external resisted coil with the correct starter switch or solenoid (depends on how new the tractor is as to whether you push a lever against a switch or push/twist a switch to activate a solenoid.) will bypass the resistor to give a hotter spark while cranking, thus making an easier start. After it is started the switch discontinues bypassing the resistor and you have a lower voltage for running, to keep from burning up the points. So all our tractors and some old pickups, farm trucks and cars (pre electronic ignition) are set up that way. Yes we have a varied collection. Now this only effects the running of the tractor if the resistor goes bad, but other then that both types run the same other then starts. Now someone mentioned the screen in the fuel inlet fitting to carburetor, checked it, again, it is definitely clean. Someone suggested the fuel bowl shut off valve and fuel tank. Drained tank, removed valve, they are definitely clean. Wanted to check fuel bowl level while running, instructions were simple enough, but carburetor doesn't have any vacuum ports or drains on bowl to hook clear line to, so had carburetor back off to recheck float setting. Someone mentioned slack in distributor shaft, removed distributor and rechecked, no play, almost like tractor has low number of hours on it, or distributor has been relaced. Of course I checked point adjustment, again, while distributor was off. Rechased all 8 wires, & battery cables, checked all terminals, cleaned all connection points, including grounds, again. Took air cleaner off and checked it again, of course oil bowl was still clean, but checked to make sure screens and inlet pipe weren't clogged with mud dobber nest. Oh, and blew compressed air through intake with plugs removed, turning motor to open valves till air blew though each cylinder, besides looking and running wire up intake while carburetor was off. Intake is definitely not plugged. Installed new spark plugs some evening (they're all running together), Tractor now starts again, and runs quite smooth while sitting still. Never did find any reason that I was losing spark Sunday evening, but at this point it hasn't done so again, so spark plugs are only parts that been changed since Sunday. I have been driving circles in the driveway, don't want to have to call the wife to come tow me back to the house. At this point it is better, but still stumbles. I have determined it is the transition from free running to load, that makes it stumble. As in driving straight it runs fine, but when I apply a brake to turn around it stumbles. I let off the brake and it will recatch and stay running unless the load is to big. This is actually an improvement as before it would just die like I turned the key off. Now, if I can keep a slight load on it and make it past the stumble it will growl (as in a load growl not something wrong) and stay running. I played with the brakes to put load on it this way. When I could keep it running past the transition, I could put a heavy load on it with the brakes and it would stay running and sound good. This makes me think timing. I know the mechanical advance is working, but do you think wear or weak springs could be causing too quick fluctuations in timing??? And to answer a couple more questions, It is negative ground. Control box, I believe you mean small box with ammeter and light switch , is still there, although it doesn't have any lights. Battery box is shop made replacement, but someone did a good job. Voltage to coil while running is a consistent 8.6 volts. I do have the alternator working and regulating correctly. I don't remember the exact voltage, but know it was in the 13.6 -14.3 spec. I also remember it being 14 something. (It's been a day or two since I ran the test and I'm no spring chicken, so specific details will sometimes be disremembered, haha) Oh and the governor is working. I have been pulling the throttle linkage at the carburetor to "rev" the engine and the governor will pull it back. Hope this answers all the questions that were asked, I really really do appreciated all the ideas. If y'all could just reach through the computer and point to the really simple thing I'm missing, I would be so so ecstatic. I know it is something simple and when I find it it will be one of those DOH! moments. I have a 4wd clutch job that I can't put off any longer, and a air brake release valve that I'm supposed to have replaced before harvest starts, customers are getting antsy. And my own haycutter to build a pto shaft for while my hay is already needing cut and gosh I can't remember the rest and maybe don't want to. So I really need this thing to go away. Thanks again, a happy and blessed Easter to y'all. LJS

 

[Fritz Maurer]

If it works I guess it's OK, but I don't understand the need for a resistor 12V coil.

 

[Jim.ME]

If it works I guess it's OK, but I don't understand the need for a resistor 12V coil.

Sounds like he wants them to have a resistor bypass circuit for starting, thus he uses the coil requiring an external resistor, which can be bypassed during starting (cranking).

 

[Wdj]

I am hesitant to mention this as I am sceptical if it's possible but I heard of a case where the spark plugs we're not grounding properly to the head on an A

 

[Fritz Maurer]

Sounds like he wants them to have a resistor bypass circuit for starting, thus he uses the coil requiring an external resistor, which can be bypassed during starting (cranking).

I mistyped. I think he's running a straight 12V coil , the way I understand it, and that's why I don't get why a resistor is needed.

 

[Jim.ME]

I mistyped. I think he's running a straight 12V coil , the way I understand it, and that's why I don't get why a resistor is needed.

I have seen coils that were called out for 12-volt systems labeled as 12 Volt External Resistor Required. These were for systems that used a ballast resistor ahead of the coil. My understanding is they were a 6-volt coil but labeled as 12-volt to avoid confusing people by handing them a 6-volt coil to use in a 12-volt system. That was my understanding of what he is using.

 

[flatheadvff]

I don't understand where the confusion comes in. It is not a 6 volt coil, it is a 12 volt coil. There is a difference. It is a 12 volt coil external resistor required. Yes it uses a ballast resistor between the ignition switch and the coil. All your 12 volt point type cars pickups etc. used them. Look up original parts for 12 volt point type Ford, Chevrolet, Chrysler etc. they show a ballast resistor. Or in the case of ford it was resistor wire in the harness, so a lot of people didn't know they had one. That was the way they were from the factory. That goes for John Deere, International, & Case, I know, and sure most others. All in all that is not my issue, once started, both type of coils run the same. I am happy if internally resisted works for you. On a 12 volt conversion using a 6 volt starter, the spin speed will make up for the lack of hot spark cold start. I was simply trying to explain the difference and why I run the system I use. Since I was having trouble, I hooked up the bypass on this one, but further determinations, explained later, found it to be unnecessary.
I have had spark plugs in really rusted threads not get a good ground, that is a legitimate idea, or concern. Especially on tractors that set in the weather and aren't covered, ie. 2cyl John Deere with plugs sticking out side of heads. These threads, however, are clean and located under the hood, so have some protection.
What I have figured out today, since I have a paid holiday and am off work. Sunday while trying to figure out ignition problems, I had a test light hooked to negative side of coil, and a spark tester between #1 plug wire and plug. Did this so I could tell if I was losing points pulse or spark when motor would stall while test driving. I had unhooked the test light and installed new plugs earlier this week, and it has been running smooth, other then under load. It isn't a Sunday, there isn't a metal of honor parade, none of my siblings were visiting etc., so dad had a chance to come look at it with me. While I was showing him everything I had done, I hooked up the test light again and figured out that weakens the spark. So me doing that, causing weak spark, semi fouled plugs from running rich (the black smoking when I first started this project) completely fouled the plugs. So removing test equipment and new plugs, plus earlier correction of timing and she runs well when not under load. Sooo we turned our attention back to fuel. Knowing that it wasn't a spark problem, we test drove it and pulled the choke to see if that made a difference. Few trys and determined that 1/4 choke and it runs great. Originally black smoking, I had removed and cleaned air cleaner. Oil cup had water in the oil, and someone had put a brillo pad in the air inlet tube. I had cleaned everything up and removed the brillo pad, since it shouldn't be there. Now, why in the world would that be there, so quickly forgot about it. Which is why I haven't mentioned it before. I had mentioned that adjusting the carb had been difficult. On closer look, carb is a replacement carburetor and apparently it isn't jetted right for the tractor. Thus found the reason for the brillo pad (equal to partial choke, but apparently too much, thus black smoke). I am researching now, to see if it is the correct carburetor even, or if bigger jets are available, as no mater how far out I adjust, it doesn't get enough fuel, without some choke. But too much choke and it stalls from being too rich, it is quite sensitive. Now that I have determined the real culprit, I don't feel like I'm getting dementia and forgetting how to mechanic. A incorrectly jetted carburetor isn't your normal range of problems on a stock piece of equipment. Thanks for all the replies. Oh, I did at least get the yard mowed today. Feels good to accomplish something, even if it is a small thing. LJS

 

[T in NE]

I have seen coils that were called out for 12-volt systems labeled as 12 Volt External Resistor Required. These were for systems that used a ballast resistor ahead of the coil. My understanding is they were a 6-volt coil but labeled as 12-volt to avoid confusing people by handing them a 6-volt coil to use in a 12-volt system. That was my understanding of what he is using.

Like Chrysler with points ignition. They bypassed the resistor for hotter spark when starting.

 

[T in NE]

Did you try swapping the old coil back? Quick way to test the new one.

 

[flatheadvff]

At this point, I figured out my test procedure was causing my weak spark. I had a test light hooked to negative side of coil to watch point pulse while test driving, to see if I was losing pulse when engine stalled. The test light was enough draw, it was weakening my spark. I am sure now it is in fuel as tractor will run out with 1/4 choke. Called owner, he thinks he has original carburetor, and is going to bring it to me when he gets a chance. He drives over road, so could be a month before I see him. Meanwhile, I've put 30 years of starts on this thing in 4 weeks, so I have a new starter and flywheel ring on the way. Starter isn't that much higher than a drive, and owner authorized purchase.

 

[caterpillar guy]

That's good seems your making headway with it now.