Originally Posted by
HiTorq
Things that can make a outboard motor not start in rough water I'm sure are the same things that can make one not start anytime, with an exception or two.
Poor fuel (bad gas), I see this every day at work. I'd say 60-70% of all motor issues we see can be traced back to bad/poor fuel. Plugged filters, burned up fuel pumps, not to mention just plain old gas that really isn't gas anymore. Poor routine maintenance See a lot of this too). Spark plugs fouled, low or no oil (4 strokes), wiring loose, etc. Attention to detail when needed, (kill switch got pulled, etc.). Read the "rookie mistakes" thread about how may of us have done this and other things, then imagine huge waves, cold water, panic setting in that the thing died in the first place and you can see how something like this could get overlooked.
I equate running a boat very similar to when I flew private planes, ALWAYS, always, always, be ready for the unexpected. Either have a mental checklist of what to do in any situation you can imagine, or have a physical checklist. Meaning, cycle everything, throttle, kill switch, key. Maintain your boat engine like your life depended on it, it might one day. Yearly/hourly maintenance, get it done. Fuel, run a stabilizer (Don's cocktail), cleaner and don't keep old fuel in the tank forever. Maintain your batteries, ensure their the right rating for your engine and then some since we all run so much extra stuff off the cranking battery, especially during tourneys. Give the wing nuts on your batteries the float test. Throw them in the water, if they float, use them, if not, use actual nuts.
Now, quite honestly I can only think of one thing that would cause an engine not to crank/die in rough water and hydraulic a cylinder or two. If you manage to somehow get enough water in be sucked into the intake, it's done. Water won't compress so the chances of the thing ever cranking again, until it's removed somehow is slim and none. I suppose, wiring coming loose could cause it too, but chances of being able to find what/where during a situation as short lived as heavy seas and the waves coming over the back and making it a lost cause again would be slim to none.
If you've done all the above to prevent anything from happening, ran your mental checklist when it does happen, and it still won't crank, then it's time to make sure you have the ability to survive. If at all possible, stay with the boat, very few actually sink to the point of going to the bottom.