when in my truck bed, or trailer, I put them in 1st gear, set parking brake, then turn the fuel off, then remove key. ALWAYS TURN THE FUEL OFF WHEN HAULING AROUND !!. they bounce, when they do this ?, the carb's float needle will not seat, letting fuel in. then I use four 2 inch ratchet straps rated at 1500lb loads. over kill ?, yes !. been down that road once..never again !..lol.