This quad has been in storage for about 5 years. I just started riding it again, after putting rear diff. bearings in. The motor started right up after all that time after just a few kicks so i know theres nothing seriously wrong with the motor. But when i'm riding, it feels a little bit sluggish. it kinda feels like when you plane out in a boat. Is this still a problem with the rear end or is the motor just sluggish after all these years.