Setting Timing

[MiCarl]

That's not a magneto ignition. It's been converted to battery ignition and I believe the timing procedure will be different.

Hopefully someone familiar with those will notice and point you in the correct direction.

 

[Waif]

Looks like a magneto was swapped out for a distributor. (?)

Glen has mentioned on a thread elsewhere in the past that might relate to your single notch (from being from a straight magneto set up originally Either the pulley or the ignition type was changed. Guessing the ignition system was , but I don't know that as a fact ).....That at low idle (475 r.p.m.) your pointer and the pulley mark should line up.
Then with throttle at/near top of range the pulley shows the advance about a half inch beyond t.d.c. mark.
If I read it right...

viewtopic.php?t=97092

 

[WildFarmall]

Hi,
You haven't said if you have a magneto, which a 1949 Cub would have come with, or a Battery Ignition unit, which came out in 1950 on Cubs. Some Cubs with magnetos were changed to Battery Ignition over the years.
The 1949 Cub owner's manual shows only a magneto. It also shows how to time a magneto to the engine.
The 1955 or newer owner's manuals show both types, and how to time them to the engine.

IH changed to the front pulley with 2 timing marks after Battery Ignition came out.
A 1949 Cub had 1 timing mark.
You don't need the 2 marks for setting the timing. Both types of ignition use the TDC mark for setting the timing.

Below is the 1949 Cub owner's manual. The experts on here recommend people read it, it has lots of info about operation, maintenance, and lubrication. There is a table of contents on page 1.
The magneto info begins on page 30. There are pics, you can see if you have a magneto.

http://farmallcub.com/rudi_cub/www.clea ... index.html

Below is the 1955 Cub owner's manual, the Battery Ignition unit info begins on page 41.

http://farmallcub.com/rudi_cub/www.clea ... index.html

For the battery ignition unit, use a timing light, and set the timing to the TDC mark when the engine is running at 500 RPM.
If the timing light is 12 volts, you can run it with a 12 volt battery, if the Cub is 6 volts, then the light is brighter than using 6 volts.
The 2nd timing mark lets you see if the Battery Ignition unit spark advance is working, the timing should gradually advance as you speed up the engine, and be about to the 2nd mark, when the engine is at full speed.

Thanks so much Glen. It seems that my tractor was converted to a 12 volt Battery Ignition unit. I do not have a timing light but I do have an old dwell meter that I have never used.

 

[ShawnAgne]

Now I am really confused. It is a 1949 Farmall Cub and when I got the tractor about 20 years ago it had already had a 12 volt battery system. Here is a picture. It has a distributer and a coil (internal resisted). I recently bought a crank but always used the 12 volt battery to start the tractor. What do I have? Where do I go from here?

If I wouldn't know better I'd think I was looking at my Cub LOL.
Anyways here is how I did both of mine, going form memory so I may have forgotten something.

Pull plug #1. Use the hand crank and find TDC. Using a timing light adjust the distributor till it comes on. I then started the motor and then hand dialed in the distributor based on sound and locked it down. Remember though if you go on sound it is sometimes advanced to far, so when I got it sounding right I backed it off a little. I didn't move either one very much but I did move them some. Worked for both Cub and 300.

I set the timing before I converted it to electronic and 12V so after I converted them I just adjusted it by hand slightly.

 

[Jim Becker]

Just static time it using the procedures in the '55 Owner's Manual.

 

[MiCarl]

Just static time it using the procedures in the '55 Owner's Manual.

I just read the procedure and have to say with modern tools there has to be an easier way to do it. My proposal below:

1) Disconnect the battery.
2) Make sure the points are properly gapped.
3) Disconnect the primary coil lead from the distributor (that's the one on the side of the distributor, behind the wire with the yellow tape on it in your picture.
4) Loosen the distributor mounting bolts just enough you can rotate it. Turn the top toward the engine as far as it will go.
5) Use your crank to position the timing mark on the pulley in line with the pointer.
6) Set your multimeter to continuity test. (If you don't have one get one. They're cheap and invaluable for someone who is doing his own wrenching). Attach one multimeter lead to the primary post on the side of the distributor and the other to a good ground. The meter should indicate continuity (I like the kind that sounds a tone).
7) Rotate the top of the distributor away from the engine just until continuity is broken. This is what causes the coil to fire and you've just set it to fire at TDC at 0 RPM.
8) Tighten the distributor down.
9) Reconnect the coil and battery.

The tractor should now run. Ideally you'd do the verification check from the manual to make sure it isn't firing early. The manual repeatedly warns to be careful it doesn't fire before TDC. I suspect this is so it doesn't kick back starting with the hand crank.

The manual goes on to say run it at high idle and check with a timing light that it's at 16 degrees before TDC at high idle. You're not going to be able to do that with the pulley as is. You could replace the pulley which seems to be a major undertaking or do some measuring and add your own BTDC mark. Personally if it runs well and has good power I wouldn't bother.

 

[WildFarmall]

Just static time it using the procedures in the '55 Owner's Manual.

I just read the procedure and have to say with modern tools there has to be an easier way to do it. My proposal below:

1) Disconnect the battery.
2) Make sure the points are properly gapped.
3) Disconnect the primary coil lead from the distributor (that's the one on the side of the distributor, behind the wire with the yellow tape on it in your picture.
4) Loosen the distributor mounting bolts just enough you can rotate it. Turn the top toward the engine as far as it will go.
5) Use your crank to position the timing mark on the pulley in line with the pointer.
6) Set your multimeter to continuity test. (If you don't have one get one. They're cheap and invaluable for someone who is doing his own wrenching). Attach one multimeter lead to the primary post on the side of the distributor and the other to a good ground. The meter should indicate continuity (I like the kind that sounds a tone).
7) Rotate the top of the distributor away from the engine just until continuity is broken. This is what causes the coil to fire and you've just set it to fire at TDC at 0 RPM.
8) Tighten the distributor down.
9) Reconnect the coil and battery.

The tractor should now run. Ideally you'd do the verification check from the manual to make sure it isn't firing early. The manual repeatedly warns to be careful it doesn't fire before TDC. I suspect this is so it doesn't kick back starting with the hand crank.

The manual goes on to say run it at high idle and check with a timing light that it's at 16 degrees before TDC at high idle. You're not going to be able to do that with the pulley as is. You could replace the pulley which seems to be a major undertaking or do some measuring and add your own BTDC mark. Personally if it runs well and has good power I wouldn't bother.

Thanks so much! This makes sense to me! I have a multimeter and will do it. I appreciate the advice.

 

[Jim Becker]

Your procedure only takes you through the first paragraph of page 44. All the verification remains. I think you have the rotation backwards. Rotating the top of the distributor towards the engine advances the timing. If you want to use a multimeter, you can simplify:
1) Skip that step.
2) Check and set the point gap.
3) Skip this step.
4) Loosen the distributor bolts so it can be rotated.
5) Crank the engine to the TDC marker (the second if there are 2 notches).
6) Set the multimeter to voltage test. Attach one lead to the post on the side of the distributor and the other to ground. Turn on the ignition switch. Meter should read either battery voltage or zero.
7) If the meter reads voltage, rotate clockwise until it reads zero. Then rotate counterclockwise until you read battery voltage.
8 ) Tighten the distributor down.
9) Shut the ignition switch off.

Of course. if you don't have the multimeter you can skip everything about it. Just rotate the distributor clockwise until you see discharge on the ammeter. Then rotate counterclockwise until the coil throws a spark. Oh, wait, we're back to what the Owner's Manual said. 8)

 

[Dale Finch]

Some cub pulleys only had the single notch.

 

[MiCarl]

Your procedure only takes you through the first paragraph of page 44. All the verification remains. I think you have the rotation backwards. Rotating the top of the distributor towards the engine advances the timing. If you want to use a multimeter, you can simplify:
1) Skip that step.
2) Check and set the point gap.
3) Skip this step.
4) Loosen the distributor bolts so it can be rotated.
5) Crank the engine to the TDC marker (the second if there are 2 notches).
6) Set the multimeter to voltage test. Attach one lead to the post on the side of the distributor and the other to ground. Turn on the ignition switch. Meter should read either battery voltage or zero.
7) If the meter reads voltage, rotate clockwise until it reads zero. Then rotate counterclockwise until you read battery voltage.
8 ) Tighten the distributor down.
9) Shut the ignition switch off.

Of course. if you don't have the multimeter you can skip everything about it. Just rotate the distributor clockwise until you see discharge on the ammeter. Then rotate counterclockwise until the coil throws a spark. Oh, wait, we're back to what the Owner's Manual said. 8)

I think I have the rotation correct. Isn't there an idler gear that causes the rotor to turn the same direction as the engine?

The whole reason I wrote up the procedure the way I did was because it can be done from one spot rather than trying to be two places on the tractor at once.

Using voltage will work but requires watching the meter to do the job. With a tone continuity checker hands and eyes can be on the distributor rather than the meter.

 

[Glen]

Hi,
The Cub has been changed to 12 volts, with an alternator, and a Battery Ignition unit.
IH used none of those in 1949 on Cubs. The parts are more modern than the 1949 system, and nothing wrong with using them.
The owner's manual I posted on the page before this one, shows what they originally looked like.

http://farmallcub.com/rudi_cub/www.clea ... age-33.jpg

Nowadays they use a timing light for timing the Battery Ignition unit. The Cub service manual says the Battery ignition unit is timed like I wrote in the post on the page before this one.
I would buy a timing light at NAPA or somewhere for it.
You only need 1 timing mark to time it, like I wrote on the page before this one.
A 1949 Cub came with 1 timing mark on the pulley.

You can check to see if the spark advance is working, using the timing light, like I wrote on the page before this one.
You can guess at where the 2nd mark would be, it is not a necessity that it is there. Only the TDC mark is needed for setting the timing.
Below is a page from the Cub service manual showing the pulley with 2 marks, you can use the pic to guess where the 2nd mark would be. They are numbered there.
They are talking about other subjects on the page, only the pic and the words below it are needed.

http://www.farmallcub.info/manuals/gss- ... 001-43.jpg

Maybe you are not done with it yet, but the fan shroud has no screws holding it on, in your pic, on the right side. It uses 4 screws to hold it onto the radiator supports.

While you have the hood off, look at the slotted holes on the rear of the alternator, if they are dirty or plugged, use air and blow them open.
I have a tractor with a Delco alternator, and the holes on the rear get plugged with dirt. There are parts inside the alt that need air flow. The dirt will blow out the front of the alt. Use your safety glasses when using the air.

 

[WildFarmall]

Glen - I cannot properly express how much I appreciate your response as well as others who have helped me with this. I could not, and probably would not, have started this without your guidance and help. Dale event sent some spacers for my final drive!. It has taken me three months so far and I hope to at least get it running in a couple of days.
1. I will look into getting a timing light. In for a dime in for a dollar? Hope that it is easy to use.
2. The picture was taken before the fan shroud was fastened on. It has already been done.
3. I had the alternator and starter serviced by a local repair shop. I can only trust that he did this right.
4. I am working on rewiring the tractor. Is there a simple wiring diagram that you recommend with my setup? I especially need a closeup of the light switch module. What about the little fuse? What amperes? My alternator has been converted to a one wire out.
Thanks so much to all.

Hi,
The Cub has been changed to 12 volts, with an alternator, and a Battery Ignition unit.
IH used none of those in 1949 on Cubs. The parts are more modern than the 1949 system, and nothing wrong with using them.
The owner's manual I posted on the page before this one, shows what they originally looked like.

http://farmallcub.com/rudi_cub/www.clea ... age-33.jpg

Nowadays they use a timing light for timing the Battery Ignition unit. The Cub service manual says the Battery ignition unit is timed like I wrote in the post on the page before this one.
I would buy a timing light at NAPA or somewhere for it.
You only need 1 timing mark to time it, like I wrote on the page before this one.
A 1949 Cub came with 1 timing mark on the pulley.

You can check to see if the spark advance is working, using the timing light, like I wrote on the page before this one.
You can guess at where the 2nd mark would be, it is not a necessity that it is there. Only the TDC mark is needed for setting the timing.
Below is a page from the Cub service manual showing the pulley with 2 marks, you can use the pic to guess where the 2nd mark would be. They are numbered there.
They are talking about other subjects on the page, only the pic and the words below it are needed.

http://www.farmallcub.info/manuals/gss- ... 001-43.jpg

Maybe you are not done with it yet, but the fan shroud has no screws holding it on, in your pic, on the right side. It uses 4 screws to hold it onto the radiator supports.

While you have the hood off, look at the slotted holes on the rear of the alternator, if they are dirty or plugged, use air and blow them open.
I have a tractor with a Delco alternator, and the holes on the rear get plugged with dirt. There are parts inside the alt that need air flow. The dirt will blow out the front of the alt. Use your safety glasses when using the air.

 

[Glen]

Hi,
Before timing the engine, set the point gap to .020", like the Cub owner's manual shows. I would put in new ignition points and condenser, if you didn't.

Below is listing for a lower priced timing light. It is just an example to show you what it is. They are simple to connect, 2 clips for the battery, and the other connection clips over the number 1 spark plug wire. The end of the unit has a light in it.
With the engine running at about 500 RPM, point the end with the light at the timing mark, and pull the trigger, the light will flash on and off, and light the pulley and mark. The mark has to align with the pointer. If they don't align, adjust the distributor, by loosening the 2 bolts holding the clamps, at the round base of the distributor, and turn the distributor, until the mark and pointer align. Tighten the bolts when done timing it.

https://www.ebay.com/itm/Petrol-Engine- ... ctupt=true

You only need a lower priced light for a Cub. They make them that cost more than this one.
You can see the timing mark easier if you color it white with chalk or something before timing it.
The light probably comes with directions, something could be different than I wrote.

Below is a pic from TM Tractor, of the charge and light switch a 1949 Cub came with. They originally controlled the charge rate, before voltage regulators were used on Cubs, and the lights. They have 4 positions, turning the knob. The fuse is built onto the back of the switch. The owner's manual says use a 20 amp fuse, on page 63.
If you still have this style of switch, you have to combine part of the original wiring positions with the newer wiring for the alternator.

Some of the people have wiring diagrams for that, maybe someone will post it for you.

The 1 and 2 positions originally control the charge rate, the 3 and 4 positions control the lights, the guys have said the first 2 positions become off, using the switch for just the lights. Then position 3 is dim front lights, and position 4 is bright all lights.
There is a wiring diagram in the 1949 Cub owner's manual on page 34, of the original way. It also tells about the 4 position switch.

 

[Dale Finch]

I would agree with Glen on the timing light...just get a very simple, inexpensive one. My big fancy (expensive) one from Craftsmen doesn't work well with the cubs.

 

[coppersmythe]

I would agree with Glen on the timing light...just get a very simple, inexpensive one. My big fancy (expensive) one from Craftsmen doesn't work well with the cubs.

right on the money . i found one in a thrift store for $2.00 . they let me take it outside and test it on my truck . , coppersmythe....................................

 

[outdoors4evr]

Most timing lights require 12v. Connect the clips to a 12v battery (use an external battery if your cub is 6v).

 

[JimCub48]

Above post , does that mean if the 4 position switch is in the 3rd or 4th position the battery is not beging charged. And with lights on the battery will drain. I have watched mine in position 3 low light and the amp meter is on the positive side . When the switch is in position 4 bright light the needle will slide to the negative side at idel. At about half trottle amp meter will move to the positive side.

 

[WildFarmall]

Thanks so much Glen and all. I will get the Timing Light. Still confused about the wiring but I will try a few things. I have the service manual so I will check that again but the picture I looked at was really small. It also shows a ground wire which I am not sure where it goes. I have a 12 volt battery system with alternator. I change all points, plugs, plug wires, condenser, distributor cap, and rotor. I gapped all as best I could.
Thanks all.

 

[Jim Becker]

Above post , does that mean if the 4 position switch is in the 3rd or 4th position the battery is not beging charged. And with lights on the battery will drain. I have watched mine in position 3 low light and the amp meter is on the positive side . When the switch is in position 4 bright light the needle will slide to the negative side at idel. At about half trottle amp meter will move to the positive side.

Positions 3 and 4 set high charge the same as position 2. Position 1 is the only one that sets low charge. As you have noted, the lights consume most of the generator output. All your noted ammeter readings are normal.

 

[tmays]

Agree you can’t check the advance with pulley as is, but no need to change the pulley. Just find the distance between the marks on a pulley with both marks and mark your pulley