Sorry Boat Question, not car question, zap from cowl after 5" rain!

86 evinrude, now the 4 cyl engine has 4 coils, year one, 5" rain in 12 hours, boat would not start, starting fluid and fired up and got spark type zap putting on the cowling. Replaced plugs and put new plug and coil wires on, year 2 same 5" rain boat would not start, starting fluid and zap putting cowling on. The boat has 4 coils, so I ordered 2 used, thought I would replace 2 at a time and look for shorts, or evidence of sparking. Now the boat beginning of the year drags, ie 27 mph vs 35 mph then kicks in and runs fine unless my daughter fails 3 times to get up om slolem. Just asking your thoughts as far as zap, I am thinking it has got to be coil or after, after is taken care of, coils soon, any other ideas?

Forgot the particulars 86 90hp evinrude vro with vro disconnected, on a lund (don’t ask unless the long story is desired) ugly green fiberglass boat.

Does the boat have a gauge cluster at the helm with a tachometer? I have heard of people getting shocks from the tach wire. If so, check the wire bundle where it exits the motor housing and up into the motor for chafing. How do the battery supply connections on the motor and battery look?

Would definitely check the wiring. At that age, if it hasn’t been replaced, it should have been a couple times. Secondly, the lower cowling should have a drain. If it doesn’t function well, after a heavy rain or running in water that can easily spash up and can settle in the lower part of the motor causing all sorts of potential electric problems with any connection in that area the next time it is run. Lastly, when has (have) the carb(s) been cleaned because of ethanol contamination. Unless you stringently store it, the ethanol can recruit more moisture and cause all sorts of running problems too. It can exacerbate a weak firing system.

If the sparking is coming from the ignition, and most likely is, then the ignition is most likely seeking a better path to ground. Something in the ignition circuit isn’t bonding to the engine ground properly.

What @Cougar‌ said.

BTW, most starting fluid doesn’t contain the oil necessary for 2-stroke motors. Bad idea.

Ah, the memories! Off topic, but we had an old mercury engine with two starters. The second starter was the reverse gear. It’d start the engine and run backwards. Good times