Does it start easily? Do you have a compression gauge to take a cylinder reading?
Have you been through the carburetor for a cleaning and rebuild?
Yes, it starts easy...and runs good for 30 seconds. Compression seems okay, but didn'y use a gauge. The carb is clean, but I did not make any adjustments.
After the problem started, I removed the bowl and the air cleaner. The bowl was clean, but I recleaned it, checked float and needle valve and reassembled. That was it, and it had no affect.