OK, try to stay with me on this one.
Also bear in mind my boat runs uncommonly well. It starts in one turn without pumping or anything first time every time. It is no different than starting a modern automobile. Its a Chevy with a Webber carb and Mercruiser ignition. 'nuff said.
I just put the boat in the water following a pretty large list of work to include:
Replaced flywheel to allow top mount starter.
Replaced steering cable on general principles.
Re -packed shaft log with the black stuff.
Finished and installed new rear seat and bolsters.
Installed a new stereo, amp and four speakers along with all related wiring, breakers and distribution blocks.
A decent list yes?
So the boat wont start. Huh? What gives? I had dry fired it before leaving the house and all was fine/ I had, of course also run it on the hose following the work and all was fine/ Now it wont start, cranks fine, good gas, no fire.
Hmmmm.. scratch head... Well, no sense clogging up the ramp, maybe its flooded or something right? So I drag it back up the ramp and try it again. Boom! lights right up and runs fine. Back in the water... nothing... back up the ramp and no problem....back in the water and nothing...Back up the ramp, starts right up. This time I just pull it out of the water a little and have my son hit the key. It fires right up so I back down and as soon as the bottom gets wet it dies.
Scratch head some more. Now Im thinking screw through wire etc etc so I unplug the harness and hot wire the bitch and go skiing and boarding for two hours because thats what rednecks do.
Well this morning I went back down with my Fluke and OHMed out the harness.
Tachometer feed dead short to ground on the boat side when wet, Open when dry.
So I figure I molested the harness inside the tube when romancing the new cable through. No biggie, 1 new wire coming up!
Not so fast.....
When I looked under the dash, this time with a flashlight and my reading glasses, (I'm 48 don't laugh.) I saw the impossible:
I had managed to get a loop of the gray tach wire inside the steering cable helm nut and tightened that sucker all the way down. How the F*&k did I do that? Probably not wearing my glasses.. LOL.
So remember I run in sea water which happens to be a very good conductor.
What was happening is that the tach wire which is the - side of the ignition coil was contacting the steering gear. When the boat got wet, enough of an electrical connection was made through the water between the rudder and propeller shaft to basically short the coil to ground and shut her down like an outboard.
Never would have happened in sweet water but you may have gotten a tingle off the wheel. The wire never quite severed and the tachometer kept working fine.
I never cease to amaze myself.
Jesus was a bare-footer.............