RedactedNarrative: Operator and his 2 friends were heading out of the Merrimack River and hit the area before the Toothpick where there was no wake zone.  He had the throttle wide open but the engine was sputtering so he slowed the boat.  The engine stalled and upon starting it up he heard a pop and an explosion and a fire erupted where the engine housing cover had blown off.  He was able to extinguish the initial fire but he noticed soon after that black smoke was coming from the cabin.  Another vessel came by and he and his passengers were able to board the vessel to safety.  Vessel and everything on board total loss.