A friend of mine has a Yamaha Timberwolf 250cc 2 wheel drive 4wheeler. On acceleration it pulls to one side when you let off the throttle it will pull to the other side. I have checked the tire pressures in all four tires an adjusted to specs, I have checked and adjusted the toe-in to approx 1/16 to 1/8 toe-in with no change to the pull on acceleration and decelleration. This 4wheeler is shaft driven, no chain. I have jacked it up with an atv jack, checking the rear swingarm, no loosness in it at the frame mount nor are the rear axle bearings loose with movement forward, backward, up, down, in or out. The front suspension is good and tight, no loosness in the steering linkage, ball joints or wheel bearings. The rear tires are Titan 489X/Ts, the fronts are Titan 489A/Ts...
Any help would be greatly appreciated.