I have made 2 trips to the UP in the last month and there has been a drop off in my top end between the 2 trips. Let me start by saying that I had CB Performance go thru the sled, rebuilding the shocks, cleaning the carbs, pv's, new track, etc. My first trip the sled ran great, having no problem exceeding 100 mph on straightaways and such, to the point where I had to get out of the throttle to keep from riding up on the sled in front of me. After that trip, the sled had been stored in my heated garage until Weds. when I headed up north again. We rode from Ironwood to HoopnHoller and right away I noticed the sled didn't have the top end I remembered from before. I had had trouble starting it so I thought I had fouled the plugs. I changed out the plugs and they looked pretty good, clean up to the bend in the electrode. The sled seemed to run a little better but I noticed that it never wanted to rev past 8000 or so. If I pinned it out of the hole, I might see 8100,8200 or so but cruising and nailing the throttle never saw more than 8000. Mid range power felt great...very snappy. The sled ran great in the turns...I weigh 250 and I kept having to back off my 150lb buddy on a Polaris Fusion. Problem was on the straights, He would put distance on me.