Help Troubleshoot my Mag reinstall

So I removed my right mag, sent it in for 500 hour IRAN and reinstalled it tonight...started engine, right mag not working. Selecting L+R engine starts and runs, selecting L engine runs, selecting R engine quits.

I had previously successfully completed a IRAN and reinstall on my left impulse coupled magneto and run for several hundred hours and thought I understood how to reinstall and time the magneto but perhaps not...questions below:

Is there any difference between timing the right mag (non-impluse coupled) and the left mag? I used the R timing pin hole on the right mag (there was a X, a L, and a R hole)...When I reinstalled the right mag, it seems like it was one tooth more clockwise as viewed from the back of the engine, as I had to clock the mag much farther (~1tooth) to get the timing box to show the points opening at 25 BTDC. I used the compression stroke of the #1 cylinder (both previously when I did L mag, and this time when I did R mag). Assume if I got the mag one tooth off, but made up for it in clocking of the mag to the case, this is ok?

Other thoughts for what I may have messed up? I noted that cylinder 2 and 4 EGT were a bit colder during runup than usual when running or L+R or L...Selecting R only and engine immediately quits without making any power or unusual firing.

I will check the magneto p-lead tomorrow. Since the harness cap has 3 screws and 4 spring loaded electrical contacts, I assume I could not have messed up the clocking of reinstalling the cap?

Do both mags fire every cylinder every 360 of the prop

with only every other firing being during the power stroke? Is this called waste spark, or do the mags only fire each cylinder once every 720 deg? Lycoming IO360M1B.

OOPS: maybe this is my problem:

Which timing hole to use: "Has nothing to do with whether the mag is mounted on the L or R."

I used the R hole since it was the right mag...perhaps it was left turning mag...

Right magneto: SN: 13050824, Model: 4370

Mags

All the modern four cylinder lycomings are left rotation or counter clockwise as viewed from the front of the engine looking aft. Just did my 0 320 with Bendix mags.

Exactly. Look at the placard on the magneto. It will say ?ROT.? with an ?L? or ?R? stamped next to it.

Last post is correct. The R and L is the direction of mag turning. Look up the data for your engine make/model, it should say which way it turns,
Next to last post: Standard mags have no wasted spark. They are geared to turn 1:1 (4 cylinder engine) or 3:2 (6 cylinder), producing two sparks per revolution. Bottom line: each plug fires once every 720 deg of prop revolution.

Once you establish the rotation of the mag from the placard, with the mag off the engine, partially insert the timing pin in the correct hole. Now comes the fun part: Turn the mag until the pin inserts all the way, seated against the shoulder on the pin. It feels as if it is seated at several places but it is not. Make sure the engine is set to the timing mark with the #1 cylinder near TDC, and install the mag. Make sure you remove the pin at this point. Then finish timing it and tighten it down fully.

Timing Pin

Thanks for all the responses...I will re-time the right mag using the L hole.

I don't have a timing pin and have been using a 1/16 allen key...I do note the multiple possible places it "feels" like it is in place, but not fully seated. Can somebody tell me the dimensions of a timing pin.

Not seated/seated insertion lengths and diameter?

I will try to find a spare one from a mechanic friends toolbox but in the meantime...

Timing

You should always approach the timing mark on the ring gear in the normal direction of rotation of the engine. If you go past the mark, turn the prop backwards a few degrees and try again. After the mag is installed, turn the prop backwards a few degrees and tap the prop blade in small increments until the timing light indicates.

Mags

For anyone with Bendix mags, I got a couple of p leads from salvage or whatever. I cut the wire off about 2" in length and stripped the end. Now instead of taking the breaker cover off the mags I just disconnect the p leads, put my short p leads in place and hook up the timing device. Saves a lot of frustration.
I have pretty much given up on the Slick mags. I rebuild the Bendix mags myself and the Bendix produces a hotter spark.