hi im trading my 04 cr85 expert for an 01 cr125. the last rider weighed 95 lbs and said his suspension was set up for his weight. they aren't sure exactly what they did to the front besides new seals and fluids. but the back had the sag just all the way up, and didn't touch the spring they said. what would i need to do to fix it for a 160-165 lb rider? is it exspensive?