Hi, I have a new x320 with 27 hours. I was working this weekend hauling loads of brush with lots of short starts and stops. So, maybe the engine never really warmed up. A few times the engine sputtered. Then when driving up an incline it sputtered and stalled. I moved her to level ground and it took three cranks held for 5 or 6 seconds with full choke to get it going again. The gas tank was full. Oil is full. Any ideas??