SnowBlower not firing after it died

Lawn Boy snowblower with Techumsa engine - 8hp I believe, maybe 10hp. Usual start-up procedure - choke on, throttle up and three presses of the rubber primer button. Third pull it started right up. Turned the choke back and it died. Nothing since. Plugged in to start with starter and just a "wwwhiiiiizzzz" Ok, so the starter is gone but nothing from pulling either. Perhaps I just never noticed but it seems there's an air sound from the muffler. No feeling of compression chnage. Pulled plug and it was black with oily stuff and a bit "gritty". Changed plug and it's a nice blue spark but still nothing. Priming gives a "sucking" sound from the carb area. Getting fuel to the carb as the float bowl will fill and drip.
Not concerned with the starter as it's always pull-started easy. Probably 5 or 6 seasons of use. Thoughts?

 

Could be a stuck valve. Check compression first. Pull the plug and tie the wire back. Then, if you don't have a tester, put you thumb over the plug hole and spin the engine over. You should have enough compression to push your thumb off the hole.