I have 18 hours and 150 miles on my new 09 Teryx. At low speeds, say from 8 to 15 mph, the Teryx lurches like the accelerator is being slightly pushed in and out. This seems worse when slow going down hill or on trails such as those with loose dirt and leafs. On hard roads it doesn't do it! Also, the motor seems rough at low speeds and when I accelerate sharply it smooths out and goes like a bat out of hell (which is great). I'd appreciate some advice because I'm taking it in for the first service soon and would like tell them what might be wrong.