My grandson was operating his father's inflatable all day and somehow the engine came off the transom and went into the salt water. It was in for only a couple of minutes. I picked up the engine and within the hour had drained the carburetor and oils, replaced the spark plug, oiled the cylinder and sprayed a liberal amount of CRC on the engine. The engine fired right up and sounded good on idle and mid-speed, but shuttered at anything over half throttle. Thinking the carburetor needed to be cleaned, i took it apart and cleaned it (a couple of times) but still had the shutter. I bought a new carburetor and installed it and still had the shutter. I connected a timing light to the plug and at idle through half throttle has a constant spark, but past that the spark breaks down. I disconnected the kill switch with no change. The engine was built in 2008 and has the "new" magneto. I replaced the igniter thinking that was about the end of the electrical issues. After replacing the igniter it still has the shutter. I am now growing an inventory of spare parts without resolving the problem. What am I missing?