runs for 40 minutes, then dies and will not re-start

[Spittybug]

Too bad you aren't a manual gear box. A simple rolling when in gear is the easiest way.

[Farrar]

Those should come right apart. Replace the 4 big bolts with stainless. This also preserves the alignment so it goes back together easily.

BTW - you can bump the engine around to TDC with the starter.

I tried bumping with the starter, but it was just too much of a hit-and-miss affair.

You're right, though - as badly rusted as that hardware was, it came right apart after an all-night soak in acetone/ATF.

I've turned a few with the fan belt. You would need to remove the plugs and get some wrench onto one of the upper pulleys.

I tried that, too.

The hardware came off. Three of the four nuts took a 17mm wrench. One took a 15mm. See if you can spot which:

IMG_6325.jpg

Give up? Bottom right.

Anyway, this is where I am now:

IMG_6356.jpg

I lined up the distributor, confirmed spark (again), sprayed some starting fluid down the carb and cranked it. The carb went "POP" and smoke came out. I think I may be 180° off or used the wrong notch on the crankshaft pulley.