The newer Arens have issues where a gas feed "bolt" in the carb gets a tiny particle stuck in it's miniature jet holes and starves for gas. Ask me how I know. Happens on quite a few small engines w/crappy gas filters.
The other thing is less than stellar motors (non-Hondas) will not start with old gas. It's not so much gum clogging stuff up, it's the reduction of octane & combustability you have to worry about. Low rpm preignition won't kill an engine, but it will refuse to start. One time I fucked with a customer's new robinson/subaru engine for 10 minutes, changed the gas on a whim, and it started in 2 pulls. "Oh the gas? It was only a year old". FYI gasoline has a shelf life of 2 weeks.
BTW check to see it has spark, obviously you should have changed the plug by now. That's the numebr 2 reason customers can't get shit started. Old plug, or left the choke on and never changed the black plug.
Cliffs:
1) check for spark
2) check for fuel (ether starting fluid)
3) make sure fuel & spark plug are fresh