M_Boats: Towing with motor attached

The M-17 I just purchased has had the outboard left on while towing for the past 12 years. I cannot see any problems caused by this, however, I'll guess it's not a recommended practice. Luckily 12 years amounted to just a couple thousand actual road miles. '92 has a very solid motor bracket. Is anyone doing this? I would think it could cause separation at the deck to hull attachment in the stern above the mount. Bill M-17 SF Bay