Have an 09 525xc. Only purchased cause a dealer had it for a pretty good deal. Always heard they were monsters and beat 450s easily. So I took it home and raced my 2010 yfz450x. 450x has a full dasa, fci and vortex. Stock otherwise. The 450 was winning every race from a roll to a dig. Pavement or grass. So I took it to a shop and had them do the carb mods I read about. Definitely improved performance but still not enough. Now they're dead even til 5th then the 450 still slowly walks away. Had the mechanic go over the whole quad when he did the carb work and he said it's all good. Valves, leak down etc. Am I missing something or is this pretty typical? Not trying to build it to be faster then my 450 just caught off guard.