Haus, check for:

Clean air filter
Idle mixture adjustment screw
Vacuum leaks between the carb and cylinder
If you don't find anything there, and it still won't idle w/o using the choke, pull the carb off and clean the pizz outta it. Check the pilot jet, that's the one that the long needle seats into. If that's clogged, it won't idle right.

Edit: You was posting while I wuz writin'.....

The fact that it absolutely won't run w/o the choke, even at speed, really makes me think you got a major vacuum leak. Get it outdoors with a can of starting fluid and a garden hose handy, start it and spray on the intake between the carb and the cylinder. If it picks up rpm, you know it's sucking it in somewhere it shouldn't.