The quad is a Kawasaki KFX400(same as Suzuki Z400):12.1:1 CR, HotCams, DRZ valve springs, CDI 10,500 rpms, Edelbrock carb, Rossier shorty pipe, Fox shox up front ... lots of other stuff.
The trailer is from Home Depot, 4x8 for $600 about 5 years ago.
The trailer plate, yep that's from...