This is probably a dumb question with a simple solution, but anyway here it goes.  I have a 74 model 43' Nautaline, twin 302's.  Last year one engine got to where it would run only if the key was held on, or a wire was ran from the coil to the battery, the boat was removed from the water for some repair, and now the other engine is doing the same thing.  Like I said, they run fine, as long as you hold the key on, or run the jumper wire.  Where would I start to look to fix this problem.  Also, the engines are of the same vintage as the boat.  Thanks in advance.