Well, since you went with DA I wouldn't worry too much about it. I don't like to think I do or would want anyone to take advantage of the their customer service, but they usually do take care of their products outside of the 2 yr warranty if it wasn't crashed or some kind of obvious consumer related cause. I've used 100:1 amsoil from the start and had my 150 on a heavy plane keeping the motor under more load. After 3.5 yrs, I sent it in between seasons just to have it checked out and I was planning on paying for anything they could see that needed to be fixed or replaced and they put new pistons and bearings in at no charge.

In my opinion, just do what DA says, don't worry about it, have fun and they'll take care of you.