Timing a Magneto for WC

So I have been monkeying with a 38 AC WC oldstyle and when I started the process she was out of time. Somehow along the way I got it close to right and now I am completely out of
time again. I have been trying to get #1 on its compression stroke and watching the mark on the flywheel through the top inspection hatch. The Mag was rotated to the passenger side
the full length of the slots on the mount. I set the points on the mag for .20 then set the #1 on compression. Then I get stumped on the mag settings. Is the gear marked with C, A,
need to be on the bottom or the top of rotation on the mag (cover off)? With a 30 degree advance the roter doesn't point at the post for the plug directly. Some help would be
great.

The C and A stand for clockwise and anti clockwise. You need the C Mark to line up with the tooth on the small steel gear that has the corner filed off.

You need to put The mag together. Then put a wire in the #1 hole and turn the drive one click at a time till you get a spark. Then the magneto is ready to install.

You may need to re-time the drive gear. Also, there are two procedures to time a mag. One is done at Top Dead Center, which I think is what the other post describes, and the other is done at 30 degrees of advance (FIRE when looking at the inspection port). I prefer the latter. My instructions below assume you have a FMJ mag.

1. Make sure the internal gear is timed properly (I think "C" is correct per the other post).
1a. Since you think it was out of time before, mount the mag to the drive, and remove the mag and drive shaft from the engine (the gear on a WC does not have any timing marks, at least mine didn't). I don't remember if you have to pull the governor apart for this or not. My WC and manuals are in Nebraska.
2. Make sure the #1 piston is on the compression stroke, and line up the "FIRE" in inspection port beneath the tractor.
3. Removed the distributor cap. Just before the Upper Left spark plug post (#1 plug) there should be one or two bars cast inside (with a small 4 and 6 (4 cylinder or 6 cylinder)). Rotate the drive gear BACKWARDS until the rotor lines up with the #4 bar.
4. Re-mesh the gear with the camshaft and make sure you are still lined up on "4" bar. You may have to remove and re-mesh accordingly since the gears are bevel cut, just make sure you are rotating the mag backwards.
5. Tighten the assembly and reinstall the governor if removed in 1a.
6. If it is backfiring when you try to start it, you might be 180 degrees out of time...

My FMJ has a coupler for easy removal. Thanks for the tips. I will try them this weekend. I believe I am 180 out of time.

thanks. I will look for that filed tooth.

You can try just the coupler, but the "coupler" part on the tractor might not be timed correctly. You need to mount the mag to the extension shaft and remove it from the camshaft. Only when the gear and the mag are timed correctly, will you be sure the timing is working. Otherwise you might be 30degrees off time with not way to adjust the mag enough.

In the picture below, your "coupler" is area "A". You might need to time it from area "B":

Update... I ended up pulling the drive from the engine. It ended up that the tractor had been timed to the #4 post on the distributor and not very well at that. Starting from scratch I pulled the drive and lining it up with the firing mark in the proper position for cylinder number one. It also was helpful to know the C mark had to be lined up with the marked tooth on the FMJ magneto too. The first go at it, it was still 10 degrees off. I found that the coupler needed tension in the connection to preload the fire point. You had to twist, lock it in and then twist it verticle to get it ready to pop on F. Resetting the drive by a couple teeth to add that tension and then putting a timing light on it to align the mag right did the trick. She starts and purrs on the first turn of the crank.

(quoted from post at 16:10:57 05/10/20) The C and A stand for clockwise and anti clockwise. You need the C Mark to line up with the tooth on the small steel gear that has the corner filed off.

You need to put The mag together. Then put a wire in the #1 hole and turn the drive one click at a time till you get a spark. Then the magneto is ready to install.

Click to expand...

My Wc Mag does not have a filed tooth which caused some consternation, I have a single punch mark on one of the teeth I am assuming is the marked tooth, Am I correct?