Bought this sled for my son, Ran alright at first, but now it wants to dog out after it gets warmed up, (5 mi. or so). THe plugs look good, the s/p wires connections are good. He stops , then it runs fine for another mi. or 2. Then it dogs down again. It starts good warm, hot, or cold. There seems to be a little coolant leak in front comming from the head gasket. It's my guess, that maybe when it warms up, it also leaks slightly into a cylinder, causing rough run. I just don't know what to think. I hate the thought of putting too much more money into this sled. What's some of you people's thoughts. I would really appreciate some input. THANKS!!!!