It seems like it was the perfect storm.
After sitting for 2 years it appears I had several problems all at once.
Took the carb apart and found the needle value was stuck, rebuilt it and ran much better - for a about 20 minutes.
Replaced the plugs and cap and rotor and noticed a big difference in performance - until I hit 30 minutes.
Replaced the coil and ta-da!
Thanks for all your suggestions. You all were right!!
