Hi, I'm new to the forums. I just recently traded my foreman for a trx400ex. I have a ton of experience with quads and any with with engines, but never a sport quad. The problem I'm having is the quad runs flawless for a while, but when I do a wheelie in 2nd and sometimes 3rd, it starts to sputter when I get into the high RPM's. Nothing out of the ordinary, it has a carb, so it's just starving for gas when it's up, but then it continues to sputter for another 10ish minutes after. Great low end, still idles, but when you get past 3/4 throttle, she sputters and loses power. Doesn't seem like it's dying out, just sputtering and not giving me everything. The guy didn't know too much about it. But it has stickers on it saying weisco and dynojets, and he knew it's bored to a 440. So I'm led to believe it has jets, and high comp pistons. I haven't really looked into it that much. I changed the oil, the air filter is clean, and the whole air box cover is just off. I plan on cleaning the carb, when I finish a long track conversion on one of my sleds. Otherwise it's a solid machine. Also any suggestions on aftermarket parts to put on? Probably going to do a build on it, and I want some suggestions. I've heard good things about steering stabilizers? Let me know!