RedactedNarrative: Victim stated he got into his boat around 06:30 hours to start it up.  He stated, he turned on the blower and started the port engine without a problem.  When he started the starboard engine there was an explosion to the rear.  It threw him forward on the bridge of the boat.  He stated that the boats HALON system kicked in and put most of the fire out.  A smaller fire extinguisher was use by Chief to put out the remaining flames.  EMS arrived and checked out the victim.  Victim did not want to go to the hospital at this time.  An hour after the incident the victim decided he would go to the hospital.  He stated his back and neck were sore from the incident.  No other injuries were reported.