Wave over transom now outboard will not run

[davidmhull]

I was out sailing yesterday on the Chesapeake bay and it got very rough. I was getting hit in the transom with a lot of following waves and my 8 hp four stroke Honda apparently took some water under the cover. It started to only run on one cylinder and then quit completely. It would not restart so I finished sailing back into the dock. When I took the cover off to flush the engine I did not see any water. Have any of you experienced this and what should I do at this point? When I go back to the bay I will take a set of plugs with me although as I said I didn't see any signs of water up around the power head. Thanks.

 

[LakeShark]

Pull the plugs and check to see if there is any water in the cylinder head. Pull the cord and make sure it all spins free with plugs out and check that water does not come out of the cylinders (indicating a hydrolock). Check the oil in the motor for any signs of water (it will settle to bottom). to do this use a straw, put it in the gear case and then cover the end with your finger. This should give you an idea of the oil column in the motor without draining it. Then check the normal, spark, fuel, etc... I had a larger 95HP merc take a wave in the exhaust and it too locked up. I just pulled the plugs, let it spin, and reassembled. It ran like a champ after that. If everything checks out fine and it still won't run you may be in for larger repairs with a blocked valve or something but don't give up as it's usually something simple with smaller outboards.

 

[capta]

All the above is correct, but you might want to look carefully at the electrical system before you delve into something more complicated. Pull the plugs and lay them so the threads contact bare metal on the block and see if you have a good strong spark when you turn the motor over.
Also, as often happens, your problem might be completely coincidental to the wave. Look farther afield if the simple water related things don't seem to be the problem. Spark plug wires, fuel lines, carb and even fuel.
I don't know the Hondas, but if they have electronics, they probably have sensors that may have been damaged by water?

 

[JimInPB]

In addition to what has already been recommended, I would also drain the float bowl on the carb into a small glass container & see what the fuel in there looks like.

If the motor turns over normally, then fuel & spark are your most likely problems. If the motor is unusually hard to turn over, then be sure that water is not in the cylinders before you cause serious mechanical damage to the power head. If she already glugged in some water while running, then it may already be too late.

You might want to give the motor a farmers compression test. Pull out the spark plugs, put your thumb over the spark plug holes, one at a time, & crank the engine. If the compression does not push your thumb up and cause air to push out of the spark plug hole, then you have a serious internal mechanical problem. If the two cylinders feel uneven, that is also a bad sign that warrants further inspection.

 

[Barnacle Bill]

Honda 4-strokes, I believe, even in older models, had an auto shut off if the seas got really big so that the motor was rolling about where oil could go into the cylinders, etc. Perhaps it quit due to that. I once had a Honda 10 HP, the old blue and white ones, that actually dropped into the sea water (salt) when a motor mount broke due to heavy seas. Luckily I had the motor tethered to the boat so I could pull it out of the water. When I got back to Key West, where I could flush fresh water through the system, I looked into the cylinders and checked the oil, etc. and all seemed well. The engine started and it ran well for as long as I can remember. I also lost a 4 hp 2 stroke to the bottom of a river and it sat overnight. The next day I put on my SCUBA gear, dropped the anchor on where I guessed it was and found it. Luckily it was white so I could see it in the murky water. I also tried to visually get some sort of coordinate when the motor went overboard to hopefully come back with my Whaler and find the damned thing. I digress. I opened up the motor, dried it out, put oil in the cylinders, flushed the fuel system and started it up and it ran fine until I sold the boat to a guy in Oregon.

 

[Crazy Dave Condon]

All good responses. If water did get into the carb you may also have to take it apart and blast a carb cleaner thru the fine ports as that can also create issues I found as dealer years ago. Just my two cents worth. But if all fails, take it to a motor mechanic.

 

[KD3PC]

IN the future, you might keep a few large trash bags (or ones large enough to cover the head unit) to cover things up with. Cheap to use, and works very well, we keep ours covered when not in use.

 

[davidmhull]

Thanks very much for all the replies. I have not responded becuase I wanted to get back to the boat and try to get it started. It started on the first pull and idled perfectly. I thought I must be living right. I went out into the bay and when I started to give it some gas it started to act up. Basically it will not take gas worth a darn. Idles perfectly. I think that all the things you guys suggested are great information but I somehow don't think they are my problem. I now don't hink taking the waves over the transom are the problem. I think (wild guess here) that the electronic control module walked the plank. I am going to go down tomorrow and pull the engine and take it to the dealer.

 

[tjar]

If it idles, but stalls when you give it gas, it's likely that your high-speed jet is clogged. Open the carburetor and remove the jet. You call hold it up to light to look through it and see if there is an obstruction. Try blowing it out with compressed air. Be careful since the jet is made of soft bronze and can be easily deformed.