Pardon the green-horn explanation in the video but I believe it covers the issue. Anyone have suggestions I could try out? And yes, baffle <> shroud. I didn't have the urge to re-record it using the correct term.
Troubleshooting done:
Replaced air filter
Replaced spark plug
Lightly cleaned carb. Insides weren't gunked up in any way.
Checked connections on ignition coil
Changed oil (prob a tablespoon was left in it before I replaced the oil...I'm a horrible lawn mower owner)
From the quick look on the video, I'd say you may have an intermittent electrical connection that is being bumped when the cover is put in place. Check all wiring for a loose / intermittent connection.