Last year I picked up a 2000 XC700. The sled has dual SLP drag pipes, V force reeds and a balance bottle. I spent most of last season dialing in the clutching and suspension, but have always had this bog right after takeoff. Especially In deep powder. Once she gets moving on the pipes she really will get up and go. As long as you keep her singing she will run strong all day. But if you let her drop off the pipes or let the rpms drop too far and try to peg the throttle she wants to sputter and bog a bit before she picks back up. The mikuni round slide carbs that came on this sled from the factory were antiques even when they were new. I am under the impression that they just cannot fuel the engine correctly, and am thinking of installing a set of modern Keihin PWK flat slide carbs instead. Only problem is where to start for a jetting spec. Has anyone done this yet? Pilot and main jets I can sort out as I go,but does anybody have any idea what needle and slide cutaway I should start with? Or any ideas what causes this bog issue.