well jus took my 09 stock rzr on 25"mudlites to the sandlake dunes in oregon for the first time this weekend, and very dissapointed. lack of power, binding in awd when going up hills, hit about 45mph top on the beach, and cuts out/loses power around 40mph out in softer sand. :/ clutch need upgraded? possibly worn out belt? any input would be great guys, it has around 650miles.. thanks..