Sounds a lot like a problem I had on my 3wheeler a while back ago.. I was out trying to start it for what seemed like an hour. I resorted to running down the street in the middle of the night trying to push start it, this all after I realized I had the run switch to off and totally flooded the engine. Anyhow that sucker started up hard and fast. Wrist throttle totally snapped full open, me looking at the stars suddenly the ditch grabbed me in what felt like bear hug and just had it's way with me. When it was over with I was laying there looking for my scandals for about 30 minutes. I can totally see how a tree could jump in front of him. I mean.. I had a whole ditch jump in front of me!