How do I get coil off to replace?

[marshall]

I have a J4 magneto and have replaced points but can't figure out how the coil comes out after removing the cover. Can't see any mounting screws. From looking at the new one, the core of it is filled with a metal bar which goes horizontally through the coil and drops vertically down either side of the coil toward the base, but I see no way to remove these so the whole unit is locked into place.

[Waif]

The bar through the coil is holding on due to magnetic force. Lift it off along with the coil .
Be careful of the coil wire. It is/was attached with the points and fits snug through the grommet it passes through if the grommet is in good condition..

[Glen]

Hi,
The coil is supposed to have a metal bar through it. Both parts lift up, and out of the magneto.

You have to disconnect the small wire from the coil to the post on the side of the magneto, inside the magneto. You have to remove the cover over the points to get to the wire. That's a good time to put in new points and condenser.
Below are pages from the Cub parts manual, showing the IH magneto.

http://www.farmallcub.info/manuals/cub_ ... 012-22.jpg

http://www.farmallcub.info/manuals/cub_ ... 012-23.jpg

I guess you posted before I did, Waif.

Also while it is apart, remove the cover that holds the rotor in place, and check the timing marks, be sure they are aligned.
You could clean the old grease out of the area, and grease the rotor gears, the owner's manual says to grease them.
Below is a pic of the gears.

[Rick Spivey]

There are two "screws" holding down the flat bar, which are then tapped in the end to accept the coil cover screws. So the screwdriver slot has a tapped hole in the middle of it. Take those screws out, drive the bar out of the coil, and then push (tap) it into the new coil. The coil also has a grounding tab that lays on the bar and under the screw, one end only.

[Waif]

There ya go Marshall , Rick's got ya.

Sorry if you're cussing me while trying to lift that bar off with two fasteners holding it....

Same alignment as the caps holes. As Rick mentioned it's the same fastener the cap screws run into.
The fasteners you need to remove next after the cap was removed are recessed into the bar.
(Round pieces like round stock threaded couplers , with slotted screw driver head slots cut across the threaded hole inside couplers).
Kinda fussy about the best screwdriver fit as far as width. But when you see the slots , it will make sense.

[Bill V in Md]

Below is a photo of a J4 magneto coil and the attachment screw.

[marshall]

Ah. The picture makes it all clear. With the generator above the magneto on mine it makes it very hard to access and these slots are barely visible on mine because of the way they are rotated. Of course with the generator in the way I can't even get my screwdriver into the slot without a lot angle.

I was contemplating removing the generator so that I can get at this better or is it sufficient to just loosen some bolts so that I can push it one way or another so that I can access the coil and cover screws?

Glen, thanks for the advice for checking the timing marks. I'm guessing if things aren't lined up, then I'm into a timing adjustment which I've been trying to avoid.

[k hutchins]

Easier to remove and retime the magneto than trying to replace the coil while it's in place. Especially since you have to thread the wire through the grommet and then attach it to the bottom side of the distributor.
Timing the mag is not that difficult. The directions can be found in the '49 owners manual available in the pdf files. Glen can supply a link if you can't find it.
A quick synopsis is, set #1 cylinder to tdc. Pull the plug, place thumb or finger over the hole and "hand crank" until you feel outward air pressure, then keep cranking until the timing notch in the belt pulley lines up with the pointer. I do this before removing the mag. Once you have completed your work on the mag, rotate it by hand until the rotor is pointing toward the 1 o'clock position. Remount the mag keeping the body of it rotated close to the block. Don't tighten the mounting bolts, just enough to hold it in place, you'll need it to move slightly.
Go back and hand crank #1 back to tdc as before, then go back to your mag, grasp the coil cover and slowly pull it (rotate) away from the block just until it trips. Then tighten down the mounting bolts. Your rotor should be pointing back at approximately 1 o'clock and you should be static timed sufficiently.
Replace your cap, wires, and plugs. Reconnect the ignition switch and you should be good to go.

Sorry if my description isn't exactly how it's written in the manual but l was going from memory of what works for me on my '48.

Good luck
Hutch

[Waif]

I put witness marks on the magneto and it's mating surfaces , and the rotor position before removing and took care not to rotate the shaft that goes through it. (The shaft mounts into slots in the governor and turns easy once the mag is removed from tractor..)
Due as much to good fortune as careful removal with those marks the timing was still where it needed to be after re-installing. But was checked anyways of course.

[Jim Becker]

Do it the way Waif suggested, easy. One step I would add is to turn the engine with the crank until you hear the impulse click before you follow his steps. To recap:
1) Turn engine manually until you hear the impulse click.
2) Mark the magneto flange and engine block so you can reinstall to the exact rotation.
3) Remove the distributor cap and note the direction the rotor is pointing.
4) Remove the magneto and do whatever work it needs. Do not turn the engine while the magneto is off.
5) Rotate the magneto backwards until the rotor points the same as noted in step 3.
6) Bolt the magneto in place and align to the marks made in step 2.
7) Install the cap and all wires.
8 ) Recheck the timing. It will be back where it was.

[Rick Spivey]

Just a note, while the magneto is off the tractor, don't spin it unnecessarily with no path for the spark to get to ground. That can burn up a coil quickly. You will have to turn it some to assemble everything, just avoid the temptation to spin it any more than necessary.

[Glen]

Hi,
After looking closer at the parts manual pic that I posted above, I see that one screw is shown in the pic, it is number 13 in the pic. The description says it uses 2 of them.