Concerning the 4' width...a stock Foreman 500(25x8x10 and 25x8x12 tires) is 46" wide. If you have modified with ITP, Douglas, or other aftermarket rim, you may likely be wider than 48" of a 4x6 or 4x8 trailer. I have been mulling over down sizing from a 5x8 trailer due to storage issues in my garage. I would love to know how it goes if you go ahead with a 4x6.