I'd try different gas. If that doesn't work, take it back and get a new one. I've logged about 200 hrs the last 2 years cutting with the same unit and never had that issue. I've also taken down hickories and oaks that are bigger than me with it. Even on them, I never had pinch issue. That said, it wanted to bog down when it got to the the largest cut area. A trick I learned early on is, when you get to the heart of the cut, start angling the cut between on side, the other and then the middle. That way you're only cutting a % of the area you'd cut if going straight through, if you follow me. The final cut comes out the exact same as if you were using a larger chainsaw, but it isn't as taxing on the saw engine, as you are reducing the amount of cut it's making through the widest portion of the tree.