Couple questions about ignition system

[Glen]

Hi,
Thanks for the numbers of the generator and starter.

They are probably numbers at the beginning, they are 11, ones.
I found online it says that the gen uses a 12 volt voltage regulator, that is all the info I saw about the voltage.
That number was not used on a Cub by IH, someone found it and put it on.
Info online shows it might have originally been used on a Minneapolis Moline tractor, but I couldn't find much about what it was used on.

The number on the starter might be 1109611, they were used for years on 6 volt Cubs.

I was going to ask about those oil cups so I'll clean the uncovered one and give them both a few drops of oil. Maybe I can find a decent stopper to put in the capless one. I'm guessing this oil is unrelated to the oil that is filling the inside of the magneto that I mentioned.

Yes, the oil from oiling the gen can't get to the magneto.

The oil getting in the magneto is probably from a leaking magneto drive oil seal, a common problem on Cubs. The seal is between the governor and the magneto.
If it is leaking, it is engine oil getting in the magneto.
If the oil leak is slow, it might take time to get into the magneto.

You have to remove the magneto, to replace the seal.
If you don't know how to time the engine, and replace the oil seal, I would leave the seal for now.
Below are pics of the drive, and oil seal. The drive is made on the end of the governor drive gear.

The pics in Jim B.'s info about the ignition system show an automotive coil, round, cylinder shaped, with connections to battery power.
The Cub magneto coil is completely differently shaped, under the cover on top of the magneto.
The Cub magneto and coil are not connected to any battery power, or wires from the battery.
It gets no power from a battery ever.
The magneto makes it's own power when the engine turns.
Don't connect it to a battery, it can damage the magneto.
I think you said it isn't connected to the battery now.

After filing the points, clean all filings off them with a clean rag. The filings will prevent the points from working right.
The Cub owner's manual has much info and pics of the ignition points, and timing the magneto to the engine. They are at the top of the page at Cub Info, then go to Rudi's Manuals.

After filing and cleaning the points, if there is no spark, the condenser may have quit and that could be why there is no spark.
They can be defective when new.
Get a condenser that works and put in, maybe you have one that was in the Cub before, or try a new one.
If it still has no spark, the coil may have quit, and need replacing.

Below is a listing at TM Tractor for the points and condenser, you can look at the pics.

http://www.tmtractor.com/new/el/367fp.htm

NAPA has new points and condenser separately, the last time I looked.

Below is a new coil.

http://www.tmtractor.com/new/el/713fp.htm

[marshall]

I’m a nutshell, do not supply voltage to the stud we’ve been talking about. If you have supplied it with voltage, then most likely the magneto coil is no good

Edit: I think it might be a good idea to post a pic of the magneto side of the tractor to give us an idea of exactly what is installed on your tractor.

You are indeed a nutshell tmays

You asked me the right question. I was taking a picture of the path of the blue wire that leads from the post on the side of the magneto and following it back to where it connects to the on/off switch on the dashboard. Another wire from the voltage regular is going to the ammeter. Then I noticed this black wire disappearing into this same area but couldn't see what it attached to. I pulled on it and it freely came out and when it touched the body of the tractor gave a good spark.

So clearly I've had a detached wire. I've got to get to work now so I can't spend any more time this morning so I didn't follow this black wire to its other end to see where it goes or to where it should attach behind the dashboard. I'm guessing it should be attached to the other side of the on/off switch. I'm sure you already know the answer to these questions.

Since the cranking motor was cranking away when I pulled the starter it had voltage, right, but this disconnected wire must be breaking the circuit that the magneto is on so that it cannot produce voltage.

My thin wrenches arrived from Amazon so I'm going to file the points, make sure the stack of wires inside the magneto are correctly tightened down and also will try to move see about that cam lobe being at its highest point when in contact with the breaker arm.


Wouldn't mind an explanation of how I might have used a meter with probes to have detected this circuit fault before ordering new points, installing them , and then going through all this.

[tmays]

No, if you got spark from that wire, it should not be connected to the on off switch. The on off switch for a magneto does NOT have power to it. The on off switch for a magneto has only one wire connected to it. The switch mount itself is a path to ground. When the switch is closed, it connects the stud on mag to ground through the switch, this killing the engine if it’s running. The mag won’t spark if the switch is closed. That’s why I suggested removing wire from post to eliminate possibility that there may be a path to ground through the switch. If you do indeed have a true mag system with a switch with two terminals, that switch is usually for a battery ignition. It can still be used to kill a mag, but one of the wire would hook to mag and other wire would hook to ground


Post pics of your electrical system. We need to see if you have a true mag system or if a external coil has been mounted somewhere

[marshall]

Hi,

Below is a new coil.

http://www.tmtractor.com/new/el/713fp.htm

This image jogged my memory of the coil. I did indeed order it and install it within the cover on the top of the magneto. I know others have been asking about the presence of some other external coil. This is the one I've got. Assuming this is what we consider an internal coil.

And there is no connection to the battery from my magneto. The side terminal post connects magneto to the on/off switch and the center terminal of the distrib cap goes to the top cover above the magneto where this internal coil lives.

Now this dangling wire near the dash area goes to the starting motor. I don't believe it connected to the on/off as I previously said. Not sure where it connected to. Image of electric system coming. Got a downpour going and pinned down with work meetings.

[marshall]

Here are the two links attempting to show entire elec system

Note in the dashboard shot the black wire going in but just sitting on the side of the on/off switch. I have a feeling it was tied to the blue wire inside a yellow cap that now seems to be separated into two pieces, one on both wires. I'll take the dash apart so I can better see where this wire should go (its other end is to the starter motor). So hopefully this is the info requested.

https://drive.google.com/file/d/17LcAoQgN0n0kA2horeJRiPN8YH7XUb-v/view?usp=sharing,
https://drive.google.com/file/d/1KtIqFfp-96S7eIEXPHv1DH22cdezWJtd/view?usp=sharing

[tmays]

So yes, you are right. Mag system. Kept sounding like there was power to the mag. All you need to get running is mag operating properly and starter to turn over so you won’t have to hand crank it. You can disregard the other wiring for now. Jim, Rick and Glen have you covered.

[marshall]

Got the instrument panel exposed a bit but don't see an obvious connecting point for this wire coming from the starting motor.
My ignition switch has one terminal with a wire going to the side of the magneto. My ammeter has a wire going to the voltage regulator. There's nothing else there to connect to. Went through the wiring diagrams on the site but not sure which one goes to this machine. Does anyone know?

Can't tell if maybe my ignition switch had a terminal break off or whether this free-floating cable to the starter motor should go to ammeter

[Glen]

Hi,
Your Cub has had the voltage regulator on top of the generator added by someone.
If the Cub is under serial number 115403, it didn't come with the IH voltage regulator, which is not on top of the gen. So the wiring has probably been changed some by someone.
The ammeter originally has a large wire connected to each post on it.

Does the ammeter have at least 1 large wire connected to each post on it.

Does the ammeter work now, and show charge when the engine was running.

There is a wiring diagram for before 115403, and another for after 115403, yours has been changed by someone, so neither diagram might be exactly the same as yours is wired.
Look on the diagrams at the wiring behind the dash, and see if either one looks like yours has.

Below are pics from TM Tractor of an original Cub ignition switch for use with a magneto.
It has 1 post, and only 1 wire is connected to it.
No battery power wire would be connected to it.

http://www.tmtractor.com/tm-tractor/gel ... ng_001.htm

The 1st system had a 4 position light and charging system switch, with a knob that turns.
The 2nd system had a 3 position light switch, with a knob that turns.
Does the Cub have either of those.

Below are the wiring diagrams.
The 1st is the older.
The 2nd is the newer.
Look at how the ammeter is connected and see if it is like either one of the diagrams.

[Glen]

Interesting change someone did to the hood in one of your pics above, so it opens.
Cub hoods don't open like that originally. Maybe you knew already.

I see in 1 of your pictures above that the clutch pedal might not have any return spring on it, unless it is the pic making it look that way.
Each of the 3 pedals should have a return spring on it, under the platform.

Without a spring, the clutch pedal would always go forward, and the throwout bearing rub on the pressure plate fingers whenever the engine is running. That would wear the throwout bearing.

With a spring, there should be 1" of free play at the top of the pedal travel.
The clutch pedal should be up against the edge of the platform when you're not pushing it with your foot.
Pull up on the clutch pedal and see if it moves up.

Look under the platform and see if there is a spring, use a light if needed.

All 3 pedals use the same style spring. The springs go on the pedals in the same manner.
I would put on a spring if it doesn't have it.

Below is a listing at TM Tractor for a new spring.
You could paint it before putting it on, so it doesn't rust.

http://www.tmtractor.com/new/cl/864fp.htm

[marshall]

From the two diagrams I see the ammeter connected to the starting motor. That must be what mine should be as my ammeter currently only has 1 wire going to it and the meter isn't showing any response. I'm going to hook it up tomorrow but don't think this is going to be the fix that gets the tractor to run.

[Rick Spivey]

Marshall,

You are correct that connecting the black wire will not likely make the cub start. But it is always a good idea to have hot wires terminated correctly rather than dangling loose.

I hope it is clear by now that the magneto does not need ANY connection to the tractor wiring, and you will kill a magneto coil if you do connect it to a power source. The magneto is a magic black box that produces its own power. The only wire hooked to it goes to a switched ground connection, which allows you to divert the magneto's power and stop the engine from running. So I am betting that cleaning the points correctly will likely put us back into a running condition. I once installed a brand new set of points and had the same no spark condition; the next day we realized the points could have a "glaze" on them, possibly something to keep them from corroding until installed. Once we cleaned them we had a spark.

Fix your black wire, and clean your points. Insure all the connections inside the magneto are properly touching, but NOT touching the housing of the magneto at any point. If allowed to touch the magneto housing that is the same as grounding out your spark, and it won't start.

And again, as Thomas suggested, you could disconnect the wire connected to the magneto post (externally), this is the one going to the switch. That would remove that switch from the equation, since a bad switch could ground out your magneto regardless of switch position. If your switch is the proper one with a single terminal, it is "out" to run, and "in" to stop.

[Waif]

So @staninlowerAL and @Jim Becker
you were trying to help me with point gapping but weren't sure of my 12 volt system. Do the pictures tell you what you need to know about this tractors configuration and the coil?

Just so my order of operations is clear:

1 I need to get the gap correctly set between points

2 Check for spark at plugs

3 If no spark, test coil and replace if bad.

So I want to be certain I'm doing this step 1 right. Currently the bottom point seems to be in contact with the top (adjustable) point and I can't set the top point back any further to get a gap. What I'm hearing is that I have to slightly rotate the fan to get the points to open a bit. This also requires turning the rotor within the distributor cap a similar distance in the same direction so that things remain correctly synched. Is that right? I'm assuming that this is only a small amount of fan movement. Not sure how to tell how much the rotor should be rotated based on fan movement. Can anyone elaborate on how I'm to be moving the fan, observing the points, and then adjusting rotor position so that I'll be able to introduce the correct gap between the points? Isn't it possible that I rotate the fan, the points open some amount, I set a gap, and then when the fan rotates around to some other position, the points again close to the point of contacting each other? Not sure how I'm supposed to get the engine correctly cranked to the position where one can set point gap and then expect that throughout the rotations the points will come no closer than the gap at which they were set.

You have two parts to your ignition points to consider. A fixed contact for one side of contact. And the other contact riding on a spring arm.

You want to set the gap to a given measure.
What causes the gap is how that spring loaded arm rides on a lobe. The lobe is not round all the way around and that is why the spring loaded arm moves.
Adjustment is made by you moving the stationary contact.
The position of that lobe which opens and closes your spring loaded contact matters when you make your adjustment.

Study your lobe. See where / how it allows points to close?
Now consider which position of that lobe has points greatest potential for open (spread / distance) position. You want to be riding on the highest point of lobe.

I'm adding a link for you to look at pictures. Does not mean the adjustments are suitable for your set up.

Look for the lobes high point and how the points relate at adjustment time.
Trying to help.
One you set the points right , it gets easier to understand. And you certainly can do so!

viewtopic.php?t=14504#:~:text=Seven%20Set%20the%20points%20on%20the%20high%20spot,gap%20as%20it%20tends%20to%20move%20when%20tightening.

[marshall]

Got it running. After connecting the ammeter to the starter, it didn't start. I took apart the distributor again and found that the breaker arm on the bottom point had sheared off. This was because when I installed the points I had left the battery connected. At some point my wrench caused a big spark when I was trying to get the breaker arm in place and it took two big chunks out of the breaker arm I guess where contact was being made. So it was weakened and probably snapped off during my attempt to start it.

So I went back to using my old breaker arm which was in fine condition. I've established a new technique for putting all of it back together while out in the field where conditions are sub-optimal. I'm going to put together a web page with photos I took of each step so if anyone else struggles with point installation like I have maybe my method will be of some help. I'll post a link in this thread when I get it done and then maybe there will be some corrections you might direct me to add. Anyway, thanks to all who stuck with me through this. As Glen pointed out my clutch is need of some work.
At some point I've got to deal with it because it is grinding a good deal when I engage the PTO and when I shift from N to 1. There is a spring on the clutch pedal but it seems kind of stretched out.

[tmays]

:worthy: Got it running. After connecting the ammeter to the starter, it didn't start. I took apart the distributor again and found that the breaker arm on the bottom point had sheared off. This was because when I installed the points I had left the battery connected. At some point my wrench caused a big spark when I was trying to get the breaker arm in place and it took two big chunks out of the breaker arm I guess where contact was being made. So it was weakened and probably snapped off during my attempt to start it.

Glad you got it started. Again, from what I understand, you’re leading us to believe there was battery voltage to the mag. Otherwise, you could poke around in the mag all day without creating a spark. The only way mag will create spark is if mag is rotated(ing)

[marshall]

Otherwise, you could poke around in the mag all day without creating a spark. The only way mag will create spark is if mag is rotated(ing)

This is perplexing. The mag was not connected to battery. The wiring now is the same as the wiring before except that free wire from starter motor to ammeter. What about the condensor? Isn't it a capacitor which can hold voltage and discharge it even when not connected to power? Perhaps this was the source of the spark?