My dads new 850 is a sweet ride, went to Hat-fieldMccoy trails in WV and rod Indian ridge and pinnacle creek. quad preformed great no problems, checked my air box and no oil, problem must be fixed.
One thing he question was how aggressive the engine breaking was maybe just needs more miles to loosen up some. stock tires not to great so we put on maxxis bighorns, best tire so far.
Cant wait to sell my 550 and get a 2012 850XP EPS

 

engine braking is more agressive cause you heve 2 cylinders with 11 to 1 compession, tats twice the back pressure of the singles