I know I talk about Yamaha a lot but I seriouslly think they will come out with the best four stroke. I mean look at what we have seen so far. We had cat come out with an ok one. Then Polaris was a little faster but worse vibration and louder. Then SkiDoo/Rotax came with their 1000 V-Twin and we see what some real life four stroke experience wins you. I bet that when Yamaha enters the field their Four Stroke will be the best. I am basing this assumption on their four stroke dirtbikes, ATVs, Boat engines, and all their many motorcycles. I mean they have the real life experience to make one kick ass sled engine. I hope to see it soon.