I am going to buy either a Honda XR250R or a KDX200. I know that both of these are good bikes for trail riding and fire roads and that is all I will be using if for except some little jumps. My dad road dirt bikes on the 1970s' and he had a four Stroke. He wants me to get a 4 stroke so that the Spark Plug won't foul. my uncle used to have a 100cc 2 Stroke and he rode trails with it and he said that if you don't open the throttle up every once in a while on the 2 cycle he had that it would foul the plug up. I can see this easily happening on a 2 stroke 125 since it is not made for woods and trails. But I know that the XR250R 4 stroke will not foul the plug while in 1st gear or just putting around. But will the KDX200 foul a spark plug or will it be just as good as the XR250R in that spot? I will probably get the XR250R anyway because I know that it will be more reliable but I just want to know. Thanks Matt. I really love the sound and smell of a 2 cycle engine.