Hi. I have the exact same Honda lawnmower and rough running with full choke only. It happened 6/17/2012, after half an hour or so of running. The engine died slowly. It can always restart with full choke, and the speed is hunting (up and down). As soon as I switch to full run or idle, it dies slowly.
The spark looks good... and I cleaned it, for good measure. Removed the air filer (cit is clean) and run without it. No improvement. Sprayed some carb cleaner in intake.. no improvement.
It is possible that I may have run with one year old gasoline, but I am not 100% positive.
My theory, is that I have spark and air. The gas supply is the problem. Maybe some dirt caight in the carburator. I was ready to take it appart and clean it, just as I saw Bucillac's note... with the issue persisting even after the carb was serviced...meaning that the problem may lie eslewhere.
Mini-motor's advice is well taken. However, Bucillac's problem was the same with the old and new carb; so, I do not think it has to do with the process of replacing the carb. Something got in there by its own. Dirt? Gum?
DO YOU GUYS HAVE ANY NEWS ON THIS ISSUE?
Thanks.