I had a metro once that had sus pump, stripped it and the wires from the tank connector to the intank pump, had melted and the wires were burnt out!!!, and they are inside, at the top of the tank, the guy had kept increasing the fuse sizes as they blew, till it finally stopped. Now that did amaze me.
As well as the brushless motor thing and the fire triangle mentioned earlier the atmosphere in the tank will remain above the explosive limit when you take the cap off as the vapour density of petrol is somewhere in the region of 3 - 4.40 relative to air (1.0)I also was amazed to find my motorbike has the fuelpump in the tank - so bearing in mind the above comments, when I open the fuel cap to add petrol, the one thing I shouldn't do is press the starter button right? only about 4 inches from the pump to clean air...
Brushless motor!
Plus High LEL levels!
That would be the "Upper Explosive Limit"
Spirit vapour moves at an incredible rate.
Google thermobaric bomb