Operator stated he was fueling V1 at Iron Mt. Marina.  Once fueling was complete, he could not get V1 to start.  He thought the engine was flooded so he waited several minutes and attempted to start V1 again.  He stated V1 would not start, so he removed the seat off V1 to gain access to the engine compartment.  Once the enging compartment was exposed, he attempted to start V1 again which resulted in an explosion (flash fire).
CADDO VALLEY                  