Just got a 2011 rzr 800 s with 26×14 big horn tires, after riding a couple of times and ESP after reading dif posts on here I really feel something is holding the power back. Gets to 40mph somewhat ok but takes a really long time to get to 50mph. New to the rzr, as u can tell, any suggestions where to start looking for issues that would cause this. Has 1800 miles on it!