I don't recall seeing that his engine is inverted.

Take the glow plug out and spin the engine with your starter to blow any excess fuel out of the glow plug hole. If it still won't spin let us know. Once you have cleared the fuel out, try starting as normal.

That's the one and only thing I like so far about the ASP .91 that I bought. I can grab the spinner with three fingers and backflip start it. Hot or cold it fires right up.