I was mowing with my International A last this afternoon. It was missing from time to time and then would run fine. I figured something in the gasline. Finally, after a couple of hours of mowing it died. I figured a gas line problem. Cleaned the sediment bulb. Checked flow of gas from sediment bulb to carb. All okay, but tractor would not fire. Drained gas out of the carb and turned on gas again. Gas flowed to carb but still tractor would not start. So I took the carb off sprayed it with carb cleaner. Put it back on and still it would not start. It would sometimes fire weakly but not run more than a few second. I sprayed some ether in it and it would somtimes kind of act like it would turn over weakly but run just a few seconds and die again. It got dark and I quit for the night.

Looking for other suggestions when I look at it again in the morning. It is converted to 12 volt with an alternator. Quick check and no lose wires. Battery is strong. Thanks in advance. Larry H.

Take a look at the points and make sure they are gapped right.

Thanks, I will start there tomorrow.

Larry H.

My Allis Chalmers B started running rough and then would not start. The material on the points that rides on the cam wore down and the points were not opening. I put in a new set and the engine ran fine.

Sounds a lot like a coil giving out on you. If it starts up and runs better at first this morning and then peters back out after a while, I'd give that a look, by checking for a good spark just after it dies.

A weak spark is not always from a bad coil. Points not gapped right that are not opening will also cause a weak yellow spark.

If points are gapped correctly & are in good shape, Try replacing the condenser. Check the rotor & cap also.

Agreed. The difference is that if the points are bad, it likely won't run any better than it did at the end of the day yesterday.

A coil on its way out will often run reasonably well when cool, but fail as it heats up. If he has that experience, I'd suspect coil over points as the problem.

If you have the 6 volt coil without a ballast resistor you may have fried your coil. Pull off a plug wire asap when it quits and check for fire to the plug. If its weak fire or no fire the condenser would be cheapest to replace. If that doesn't fix it buy Napa's coil with a builtin resistor p/n IC14SB for about $18.00. Hal

Folks

This morning I took off the spark plugs and looked pretty carboned up and wet. I checked the spark by placing the #1 spark plug on the engine block. I got spark but looked kind of yellowish.

Interesting, I took off the rotor and distributor rotor looked like it had some oil on the inside. I cleaned it off. It would fire a bit.

My guess is weak spark. I think I will run into town and get a condenser and points. They are pretty cheap.

I suppose some chance coil is fried. It has been converted to 12 volt but looks like there is resister in line. I have another coil around here somewhere.

I will keep folks informed of what I discover.

What is they say, "Good judgment comes from experience. Experience comes from a lot of bad judgment?"

Larry

That ballast resistor may be the problem. Hal

Folks, Oops. It has a magneto. Never paid too much attention (obviously) but it has a magneto and converted to 12 volt alternator. Now what?

Larry

Other then the comments related to a ballast resistor, all suggestions are still valid.

Jim, Thanks. Not to complicate things, but I took the top off the magneto just to see if there was anything lose. There is a leadout wire that is not connected to anything. Now from my manuals, it looks like it should be connected to the condenser. However, that is before the conversation to 12 volts. Should it still be connected to the condenser (and is that the program).

Thank

Larry

You need to clean the points with some 320 wet or dry until shiny. Set the point gap at .013" if they're pitted replace them and the condenser. Your coil may be weak or the magnets may be weak & don't have much magnetism. Touch the magnets with a flatblade screwdrive. Should attract it with a lot of effort. If it's the IH4 mag your Case/ IH dealer may have the points, condenser & coil. Napa probably has them too. Hal

Is your magneto still functioning as a magneto or has it had an external coil hung on it? If it is still functioning as a magneto with the internal coil, that primary wire out of the coil has to be connected to the condenser or it will not produce any spark.

If it was converted with an external coil and uses battery power, then the internal coil should be disconnected and the ballast resistor comments are back in play.

If you clean the points with sandpaper, you might as well go ahead and replace them. If they weren't junk before, they will be after. Only use a point file on them.

Jim, Thanks very much. Now it has an external coil and what looks like a condenser hung on the outside and connected to where the grounding switch cable connects on the outside of the magneto. I do not see a ballast resistor, unless the coil is the type that has one internally. I do not know the function of that condenser on the outside.

There is too much grease on the inside and probably some got on the points. The points are in sad shape, and I will replace them. That may be the problem right there. As you know, there is place to put a modest amount of light oil, but looks like someone got heavy on the grease. I will replace the points and set the gap and see what happens from there---unless you or someone else suggests something different.

Thanks. A big help, particularly on what to do regarding the primary wire. Yes, I will stay away from the sandpaper, and try not to get greasy hands on the points. These are times when I need smaller fingers. Almost could not get the screw loose to get the bottom part of the points out. I had visions of stripping the head of the screw. Who knows the last time the points were changed.


Larry

Hal, Actually, I had a coil, condenser and points on hand. Probably intended them for one of my other tractors at some point. I looked at TSC and the rotor is different in their tune up kit. So, the gap is .13 for this. I had thought .20. I looked in my manual, and for magneto, I think it said .13 also. I think I am getting there (see my response to Jim Becker).

Thanks

Larry

Larry

I want to clear up something. I have had the tractor probably 8 or 9 years and it has ran fine. However, I do not see an ballast resistor before or after the coil. I suppose the coil could have an internal resister but the coil has been painted over so I cannot tell what it is. I assume for a 6 volt coil, one needs a ballaster resister before it.

I do not know if the coil is bad or not. The points certainly are.

For a 12 volt coil, does it need a ballast resister after it so 12 volts to not go to the points and burn them up?

Here's a mag that's been converted probably similar to what you have using an external auto type coil. Hal

Hal, Interesting. My magneto has been disconnnected. The center wire out of the distributor goes to the coil.

Now, I am not seeing ballast resister on mine either before or after the coil. I assume unless there is an internal resister there should be one before a 6 volt coil ...and should there be one after a 12 volt coil??

Thanks, Larry

There are two types of 12v coils. One is essentially a 6v coil that DOES require a ballast resistor inline ahead of the coil. The other type is wound internally to provide the necessary resistance and DOES NOT require an external resistor. You have a paint problem on the existing, but a new one should be clearly marked as to which it is.

In no case would there be a resistor inline between the coil and the distributor.

It would seem so but one day I parked the tractor running fine and the next day I could't get it to start. Changed the points and all was well.
Stranger thinks have happened.

Well, I put on new points and even got the condenser out of the mag and replaced it---since it came with the points from Case-IH.

I am getting spark from the coil. I crank it a few seconds and then just when I stop, I get a spark from the coil wire to the engine block. Don"t know if that is enough.

However, no spark from spark plug coming out of distributor.

Now, I found that the where the distributor rotor fits into the distributor gear, the distributor gear has a piece out of it so the rotor does not fit tight into the center notch of the distributor gear. I assume the timing may not be able to set right since the the rotor will move a half inch or so either way.

Perhaps that is the trouble.

I will see if either Case-IH or a local repair shop have the distributor gear of if they are still available. Might take a few days to get it.

I tried changing the timing different ways to account for the movement, but still no spark. Put #1 piston at TDC (check flywheel marking and also used a piece of wire down #1 cylinder). Set rotor so pointing at about 2 o'clock e.g. #1 cylinder. I tried it both at the back and the front end of the wobble, but still no spark.

If that is not the chip off the distributor gear and the resulting wobble back and forth, then I am baffled. I think I have the timing right and even put on a new distributor cap.

Any and all advice welcome!

Larry H.

Well, I finally go the a started tonight---after a month of messing with it off and on and waiting for parts, etcl. I appreciate all the advice. What eventually I found most helpful was John T. Nordhoff"s "Troubleshooting a Battery Powered External Coil Type Ignition Sysem" that he posts on the Farmall Forum and perhaps elsewhere.

What was wrong. Well, it still could have been several things. The point were pretty bad. The existing internal condensor was bad, and the previous owner had put one on externally. So I put on new points and a new condensor (which is fun to put into the magneto).

The distributor gear had a chip in it so there was lots of play in the rotor clockwise and counterclockwise. So I replaced that.

I had the coil checked and it showed good. I had the ballast resister checked and it showed 1.5 ohms.

So late this afternoon I started down Nordhoff's checklist. Now under 2a of his list, is says I should get on the ciols high input side "around 6 volts on a 12 volt sytem that used a 6 volt coil plus an external Ballast Resister" with the ignition switch turned. I get 12.69 volts so I do not know what is going one. Does the ballast resister reduce the voltage or just the ohms? So in the back of my mind I am still wondering if I have a problem.

Anyway, when I got to 5a, my test light did not come on. I went and double checked the points to see if they were opening. They seemed to be and I double checked the gap, which I set at .020 (sorry for previous misstatements about this). Still no light. I took off the lead wire to the points at the points (thank goodness I did not have to take the condenser out again...it is a real pain to get in and out). I noticed a little gap of wire where the wire goes into the connector. I put some electric tape over it and then put the wire back on...trying to keep it away from any metal.

I ran the starter again, and the test light flashed.

So, I put the distributor gear cover back on, along with the rotor and the rotor cap. I ran the starter and low and beyond, for the first time in a month plus, the engine started. Now it sounded a bit funny, but I thought it might be the results of the adjusting with the carb when the tractor first died. I worked with that a bit but no change. About the time I was going to check the ignition sequence. the radiator hose broke, and I shut the tractor off.

Now the firing order was off. I thought it was right, but when I checked what was on the engine, I had it wrong. I don't know if have the firing off cause the engine to overhead and the hose break (it does not have a pressure system) or it is simply co-incidental.

Anyway, I do the more hose and clamps and will replace the hose tomorrow. Do I have to take the bolts out that fasten the fan housing to the engine to get the hose on???

I hope tomorrow night I can report complete success

Thanks for all the advice and help.

Larry Hardesty