No spark on 185 mercruiser 1984 sea ray lumberjack

[Bitchless (boat name)]

I have a 1984 Sea ray amberjack with twin 185 Mercruiser this weekend I lost spark on my starboard side motor. I found that I had a bad ground post on my coil I have replaced it and still have no spark wondering if anyone has any ideas. I had the dwell on the points and timing set and there is still no spark. The boat has been running perfectly for the last 2 months curiously the same thing happened last year and I thought I had everything fixed as of this spring. I also tried running a jumper wire on the positive side of the battery to the positive side of the coil with no luck.

 

[dvx216]

Get a volt ohm meter disconnect wires going to your spark coil and take a ohm reading it should show a resistance reading if you do not see any resistance it is an open coil it will need replaced.If it shows a resistance reconnect your coil then set your meter to DC volts and where the small wires go on the coil take a voltage reading with someone starting the boat you should see 12 volts there.If all this checks out make sure your battery is fully charged some times if a battery is getting weak it will crank the starter but will not have enough charge to make a spark.If you find you have another bad spark coil make sure the bearings are good in the distributor remove cap make sure there is no play in the rotor shaft.Another thing that can burn up spark coils is bad alternator diodes so pull the alternator and have it tested at Napa or better yet a ignition shop the repairs alternators.Oh there is a plus minus connection on the coil make sure you hooked it up correctly.