The fuel may have gone gummy. While it is expensive, Mechanic In A Bottle seems to work wonders at clearing out the gum. If gum is not the problem, the additive is not harmful except to your wallet.
Either the carburetor jet is clogged, by gum or other debris, or the fuel flow is inadequate. Be sure the tank shutoff is fully opened.

Thanks bus_driver, I pulled the carb off and cleaned it throughly... but will try checking all the lines. I did drain as much gas as I could, and added some premium and ethanol treatment (not sure the brand right off hand)

Had not heard off Mechanic In A Bottle...

May try looking at the lines going through that shutoff. There was some gummy residue on the bottom of the carb tank, so possibly there's more in the lines. If gets enough fuel through it to run for a while with choke turned on. But only if I start with starter fluid...

Thank you for the advise, really need to figure this one out so we can get our winter garden planted!

Thanks for the advise @rcbe. I'll give that a try. Nothing to lose at this point :)

One of the jets is plugged. I'm not sure what system is in that carb but if there is a pilot jet/main jet configuration, the pilot jet is plugged from sitting. It's the smallest orifice in the carb and plugs up the fastest. A single wire from a barbeque cleaning brush does wonders at cleaning them out. Run a tank of sea foam or stabil fuel stabilizer at the end of the season to stop this.

Tiller fixed and running! A mechanic friend recommended using diesel fuel to soak the carb in overnight, I tried the little wire trick, and that must have cleared up the issue!

Thanks for all the recommendations and help!

And when it will be parked for several months shut the gas valve and let it run 'til it dies.
Mike