I have a shorelander trailer w/ rollers. When either launching or loading my boat (Lund 1600 SS), the engine must be in gear (forward) and throttled up to keep the boat in position so that the trailer's winch strap can be removed/attached to the bow eyelet. When launching the boat when the trailer is in the water, the boat will roll off the trailer w/o the strap/chain being attached, so much so that you have to put the boat in gear, and throttle up to remove the tension in the winch strap and to be able to unhook it. Is this normal, Other roller trailers I have launched w/ require a push, or have to have the motor in reverse to pull the boat off the trailer. I would prefer not to have to be throttled up to remove/attach the winch strap. Is there any adjustments that can be made for this, or is this norm for a roller trailer?