Yes, its true. And I pride myself on always getting a mechanical device running no matter what is wrong.
Yesterday we took my boat to City Island. It is a small Island about a mile long and a few hundred yards wide in between the Bronx and Queens in NY.
We go there often because the place is famous for great seafood restaurants on the water that you can get to by boat.
We were supposed to pick up some friends at a marina there where they have their boat and sail around to the restaurant.
We made it there and picked them up with no problem.
We pulled away from the dock about 5' when one engine stalled.
I can run the boat on the other engine but not very fast and with no power steering. You practically have to sit on the steering wheel to steer the thing so I had to pull the boat into a slip in the marina to repair the problem.
Normally when that happens it is a simple repair like a loose cable, cracked distributer cap, short circuit etc. So after trying those things to no avail we decided to drive on the Island to the restaurant. I hate driving to restaurants by car in the summer.
Anyway after dinner we came back to the marina and now it was after 10:00 so we decided to open some champaign and hang out for a while before we went to sleep.
The boat is self contained so we slept on it. Our friends there have a larger boat in the next slip.
This morning I woke about 5 and sat out side to watch the sunrise over the sailboats. It was really awesome. Then I took a walk on the island for some coffee.
We went to breakfast in a cool place on the water then went to buy some spark plugs. I knew that would not fix it but what the heck.
Then my wife and I headed back to my marina on the one engine.
We arrived there in about an hour, tied the boat up and went home.
I went back to the boat today with a bunch of tools to fix the thing. I used to be a GM mechanic and have no problem with engines.
Until now.
The engine turns over well, has good spark, has good gas, and compression. It should run.
But it don't.
Luckily I have two engines so I can exchange parts between the engines to try to find the problem. I swapped the carburator, computer, and distributer guts. Nothing.
So now on monday I will go back with my compression tester and timing light. There is one more module I could try but it is a horror to remove and you really need to be Houdini to get to it.
The marina would charge me $275.00 an hour to work on it and thats not going to happen.
I doubt the mechanic there could find the problem anyway.
Now it is a quest and I am excited to try to find the problem.
I am going to be more excited If I fix it.
So far, there has not been an engine I couldn't fix and I hope this isn't the first one.
Engines used to be simple but now you need to be a computer whiz to work on them and common sense does not work any more.

is there a vacuum leak? possibly bad injectors?

not knowing the size or make of the motor doesnt help but im giving it a shot.
more then likely its that hidden module ,eh?

are these I/O's? if so what are the engines?

Im GM certifed as well as ase master.

No injectors, carburated.
4.3 liter Merc Cruiser. GM engines, IO.
No vacuum leak. No kill switch, no engine reset.
I am hoping that it is the Shift Cut out switch that I didn't even know it had.
I will look for that switch on monday and test it.
I am not sure how that switch cuts out the engine, if it cuts the spark or severly retards it. The spark is good at all the plugs. It died as I put it in neutral from forward which is what the Shift cut out switch is supposed to do for a split second.

That's a bummer but sounds like you might be on to something with that shift cut out switch.
At least you had a dock and some champagne though..

Ahh another fellow new yorker, it was not tooo long ago i was up by city island, me and some buddys went fishing off the riptide about 2 weeks ago.

Happy days are here again, I fixed the boat today and it was a simple thing. I was hoping that it was the shift cut out switch, but it was not.
I tested the compression and that was good so that eliminated a lot of expensive, pain in the butt problems.
I checked the timing which was perfect. I tried to start it again, and nothing.
I again pulled a spark plug to test the spark and it had a nice strong spark so it could not be the coil.
It was the coil. I still can't figure it out but I switched the coil and it started right up.
It is never the coil if you have a spark, but it was. $40.00 later and it was as good as new. I took it out and burnt up $50.00 worth of gas just to make sure.
A great end to a perfect day.