I'm not sure if I want to say this outloud, but I think I found the problem...
The gas cap is leaking.
I finally got my shop cleared out enough so I could park it inside. Geez that thing smells like gas! I thought for sure it was just the exhaust so I turned on my big fan, half hour later it smelled just as bad.
I've been keeping the tank completely full, because my fuel gauge doesn't work, and my bedside is soaked with gas. I guess fuel caps weren't supposed to last 37 years.
Keep in mind, here in Oregon we aren't allowed to pump our own gas (
) so this isn't something I'm used to checking...