I Know people that haul them standing up and haul them FAR
it can be done, but IMO< you need to remember that oil will move, so once you get to where your going, and set atv back down, you need to wait a while for oil to maybe drain back where it should be, before starting or running
I don't like hauling them that way, but it can be done !
if your trailer is NO 6 ft wide and 8 ft long you should be able to fit 2 atvs on it, you just need to modify the way maybe some to allow for side loading, will be tight, but again, it should be do able!
and have so ask, does your trailer have a a 2000 LB axle or a 2000lb payload on trailer?
most single axle trailers are NOT rated to haul 2k,, some are, so I would make sure on this!
my 8.5 x 10 ft trailer only has a carrying capacity of 1200 lbs?
but its a torsion axle and NOT leaf springs
and only a small 4 lug set up!