70hp chrystler problems

[chrystler70]

i have a 1973 beecraft runabout 15ft it has a 70hp chrystler and the people i bought it from said it needed a brain box so i bought one and it still wouldnt fire. me and my dad hot wired th ignition and it fired one ime so i tried i bypass the stator just to check it. i ran a hot wire from my battery to the hot side of the coil and it blowed my coil up. did it burn mybrainbox out to or just the coil. and is this motor brand even worth fixing