I have had a pre-owned Honda Harmony series lawn mower for two years. It’s a great mower! But the last time I mowed, toward the end of the job, it stalled out, so I rolled it back into the garage for next time. Next time I tried to finish the job, it started strong then stalled out after 5 seconds at best. I've tried everything and it still just starts, then just dies out after second. It has gas, oil, a new spark plug and a clean air filter. Someone suggested either the choke or the gas “float”. I need to cut my lawn at SOME POINT again, but at this rate, it ain’t going to happen since I can’t find the root problem. Any ideas? Thanks so much for your help. :)

Sounds like it picked up some particulates in the fuel system. Flush fuel system. Tank, hoses and carb. At least the float/diaphram area. Doubt you have to dissassemble beyond that.

You can strain the fuel through a folded paper towel. Circular paper towells work best.