[Pvmt-Pndr]

I got her fired up. Checked timing and it was at 16 degrees at idle. I could use some help here... I restarted the timing down to 8 degrees. The little bit of info I've found says that these tall deck engines like between 6-8 degrees. I went down the street and back. It was still popping and carrying on but a good improvement from idle to about 2800 and then it would start poping again. I parked it and got ready to retard it down to 6 degrees and it shut off... No signs no warnings like someone hit the key to shut it off. I got it started again and moved the distributor the slightest bit and my buddy who was watching the light said it dropped off below the pointer and died as soon as I moved it.
Now I've tried moving it back and it will not fire! Any ideas what I might have going on here and advice on how to get it where it should be? Is the info I found correct that the timing should be 6-8 degrees on this engine at idle?