you are correct....103 HP show in rotax info I have.....so 27+ HP difference...I was looking at the HO specs by accident. As for the 399lbs sled...its happening ....everyone will find out tomorrow.....the reports for the 435lb sled are for the non X model....the X comes in even lower. and the TNT has all lightweight body parts, all alum. shocks, etc. and the 500SS is around 10-12lbs lighter I think it is, than the 600SDI. The X model 120" MXZ 600SDI is spec'd at 418lbs. Its a toss up as far as I am concerned....DOO has the weight advantage and HP to go with it for the 800 class, but Yami has the engine reliabilility, I wish I could combine the 2.