Honda carburetor blues...

I've been having a problem with my Honda GCV 160 recently.

Neighbor was using it and accidentally ran over a bag, force stopping the motor. Cleaned the blades out and tried to run again, just spluttered but didn't turn over. It sat like that for a while, no luck on turning over.

I took the carb apart and cleaned all of the components thoroughly with carb cleaner, reassembled and it actually ran nicely for about ten minutes. It then slowly revved down and stalled, and now it won't run again.

Is it an air intake issue? Bad gas? I put a new air filter in, too.