I can't quite see from the photos but are you using a vapor carb or liquid fuel, Most of these models are very sensative to the mixture needle which is more like an on/off switch than a fine adjustment so easy to flood them. The vapor carb is what Jan found worked best on this one.
Is that motor being used as a starter? if so you want a way to take the load off as the engine starts, a cordless drill is the more common way to power start them with a simple dog drive though I usually flick the flywheel over by hand. If it is being used to generate then take it off until the engine is running sweetly.