I need help
Is that 4100# dry weight or maximum trailer weight (GVWR)? If it is the GVWR, then it may be possible to tow it, since 4100 is enough less than 7100 that even if the 7100 is 'over-enthusiastic', it should still be within the weight capabilities of most 1/2 ton pickups. If that is dry (unloaded) weight, than it is much less likely, since you are going to want to have accessories, personal stuff, food, water, sewage, etc which can easily add lots of weight to the trailer. And 10 to 20% of the trailer weight is applied to the truck as pin weight, which can cause the GVWR of the truck or rear axel to be exceeded.
Is it a shortbed or longbed? Short beds can have trouble with 5th wheels, although that can be reduced by getting a sliding hitch and/or extended pin box on the trailer.
Is it a narrow bed or standard width bed? If you have an extended pin box, it can sometimes run into the side rail way before any other truck to trailer contact occurs.
Is the truck lifted any? Trailers are usually set up for stock height vehicles, although it is sometimes possible to raise them a bit via a process called 'flipping the axles'...
