1968 merc 650, only runs with #2 plug wire removed!!!

[Sunken Boat]

This outboard is on a 1965 14' Arkansas Traveler, The engine ran so sweet until the entire boat and engine sank! It was submerged in fresh NH water and I displaced the water. After several days of attempting to start the engine it has started, but only with the #2 cylinder ignition disconnected! This discovery was made while cranking with the plug out checking for a spark. It then started up on the 3 remaining cylinders! With #2 connected it backfires and sputters only. Disconnecting any other cylinders plug does not help, only #2. It will even run(more roughly though) with the #2 plug inserted in the head but with the wire disconnected. The ign is providing a very strong spark even on #2. This discovery was made today and tomorrow I am planning to disassemble the distributor cap/rotor to inspect. I am well versed with auto and 2 cycle systems, but am fairly new to outboards. How could one cylinder screw with the others?...most likely a short? I need to rotate plugs to eliminate that plug. I have a dvom, what else can I check that is not visual. Please help...

 

[Fuzzytbay]

Re: 1968 merc 650, only runs with #2 plug wire removed!!!

Are you 100% sure you have the correct fireing order? Also if the motor was completely submerged, the trigger needs to be taken apart and dried out. If you didn't do that, the answer to your problem may lie there.

 

[Sunken Boat]

Re: 1968 merc 650, only runs with #2 plug wire removed!!!

I got all the water out of the distributor cap and trigger assembly. The motor runs great! ThanKs

 

[Fuzzytbay]

Re: 1968 merc 650, only runs with #2 plug wire removed!!!

Good, now keep an eye on the boat, I have two that think they are submarines!!