Boat not starting while in the water
 

Have an odd problem here - got a 1989 Four Winns boat that doesn't want to start while in the water.

It starts fine while on the trailer with water connected to it, but once its in the water, she doesn't want to start...

Thoughts? I was told to check exhaust flaps in the out drive, as they can break and there may be too much back pressure. The carb was rebuilt a few years ago, but it made no difference for the starting issue.

The motor is a 3.0 4 cylinder, and it has an alpha one drive.

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Ran a quick check:
First, did you check for spark when it doesn't want to start?

Found this real quick:
Here's a whole page of WTF:
https://www.google.com/search?q=1989+Four+Winns+boat+that+doesn%27t+want+to+start+while+in+the+water.+&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb#channel=sb&q=boat++won%27t+start+while+in+the+water.&rls=org.mozilla:en-US:official

I have a chain saw that won't start in a tree or on a ladder. I know it doesn't help, just saying.

Rock,

Start by throwing a jigger full of gas in the intake and then try to start it. If it spits and sputters even a little bit, then you know you have spark and can investigate the fuel system. If it won't even spit, then start investigating things that might interrupt the ignition system when in the water. This allows you to take the correct troubleshooting fork in the road.

Hope this helps.

I could hardly recommend throwing gas down the carb and if it doesn't work then start working on the ignition/spark check. That's a recipe for an explosion. Don't handle gas then try to get a spark...

The op needs to post a bit more info for us to solve the issue. The neutral safety system suggestion is a great place to start prior to everything else as someone suggested earlier.

Are you kidding? I've done this as a troubleshooting step hundreds of times in my lifetime with no negative results. It's a very common troubleshooting step.

The only time it gets dangerous is when someone gets the bright idea to continue pouring in gas while someone is cranking the engine. THAT is when disaster can occur.

To do this safely, pour about a jiggerful of gas in the carburetor or throttle body, then set the gas container away from the engine then try to start the engine before the gas has a chance to evaporate. If it spits and pops even once, you know you have spark.

Not kidding. I had to help deal with the outboard mechanic who had with third degree burns over much of his head because he was dealing with gas and then checked spark... it's a bit safer to check spark by pulling a plug wire off the plug and hold the wire with your bare hand- you'll feel the spark and no need to deal with open gas.

Five will get you ten that the guy burned himself pouring gas in while cranking as I described. The only other way would be if he was close to the intake track while cranking. Not smart. In fact it's a good practice to slip the air filter back in place before cranking if you will be near the intake tract.

Checking spark as you describe will only verify that it is making spark. It won't tell you that it hasn't jumped time. My tried and true method is very quick and effective.

You can grab all the spark plug wires you wish. I'll pass.

X2 on that. Boats aren't like cars. Fumes can't accumulate in the bilge of a car.

You don't know this guys level of mechanical experience for one and personally, I'd check for spark by grounding a plug wire (phillips in the boot)......whether or not you've been careful in the past reminds me of Carl Wallenda.

As for checking timing...you're way down the quick check list......

Spark then fuel....that quick.

Not talking about adjusting timing, only knowing that it's close enough to start and finding it out quickly.

Sure there are plenty of ways to check spark, but a small amount of fuel, get out of the way and see if it spits. Nothing quicker and nothing more certain for moving along in the troubleshooting process.

IF this is a boat with limited ventilation in the engine compartment, then Kerry is right about being careful with gas.

Not me.

Any Winn has bilge pumps.....but not for this.
To get your jigger of gas you either need a can of gas or take off a fuel line....in a boat on the water. Can with way more than a jigger and not pouring like a bottle of vodka....in a boat....

Well what do you mean doesn't want to start? Turns over? Turns over and doesn't fire? Can you hear the spark? Do you smell gas? Does it fire idle and die?

Very good questions.

You're experiencing, what is known in most circles, Murphy's Law.

How old is the fuel? I've seen this happen before, and a tank of high octane was what it needed.

I'l admit...I'm just spitballing here. I don't know crap about boats, only what I've seen other people go through.

Where's Gus Wilson when you need him?

I don't know why your post made me think of this JP, but I wonder if maybe there is water in the tank that is not exposed to the pickup when on the trailer, when at a different angle in the water, it's picking up water?

Maybe this worth checking rock.

Wow, what a thread. Can we get back to my chainsaw now?

Go with Stihl silver mix.

Where IRock get to?

Is it my imagination or is there a faint hint of a pattern of iwrock’s motor vehicles?

Boat will crank, but will not turn over. Sometimes, it will want to start, but just won't get firing on all cylinders. I've got new plugs in, and checked the spark, and so I'm good there. I've got them gapped correctly to spec as well.

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She will crank, but not turn over. I've verified it has spark

Can't smell gas when its in the water.

When I start it on the trailer and drop it into the water, it will run fine all day, as long as I don't let her idle too long or turn her off.

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This one was given to me in exchange for some computer work for friend. I wouldn't have willingly spent money on this with these problems.

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I wonder if you fuel filter is clogged.

why would it start out of the water?

You mean does crank/turn over but not fire up/sustain? Perhaps the issue is exhaust restriction. The water is exasperating the issue? Did something nest up there?

If you pump the throttle w/ air filter off, can you see spray shooting down the carb throat?

Air and Road mentioned the angle of the boat and the fuel in the tank in/out of water.....wonder if it has debris in the tank bottom.

Dual fuel tanks?
Try switching to the other tank if dual?
Maybe pump some gas into a container and check for water in fuel.



I had a boat and one of the side tanks vent had come loose and rotated the vent forward and was getting spray all the time.:eek:

LOL...doesn't really matter.....you are enjoying the boating experience......

Sitting long enough for the fuel to get through. When it idles the fuel pump isn't working hard and doesn't draw enough fuel into the carb so it dies.

I'd bet it has a electric pump.

Fuel pumps push fuel pretty well but they don't suck fuel worth a damn. If the fuel filter is on the suction side of the pump the system won't work. There should be a screen (easily cleaned) on the suction side and the filter should be on the discharge side of the pump. The screen protects the pump from the boulders in the fuel lines and the filter protects the carb from clogging. When the boat sloshes the fuel in the tank it stirs up the sediment and/or water in the tank and you no go.

Correct on the first part.

Not sure... A friend here at work was telling me there are exhaust flaps in the exhaust that are supposed to keep the water out/backpressure down, and that if they fail, it could be a PITA to start while in water.

I never heard of flaps in a marine exhaust but anything is possible.

Did you check the compression?

Haven't done that yet - wanted to give her a good running first because she's been sitting for ~2 years.

Read the link I posted

Just caught it - that's what the guy at work was telling me to check.

Know where they are on a Four Winns with a 3.0?

i would imagine it cant be to hard to locate them, follow the manifolds down? ive only ever worked on outboards.

Cool, I learned something.

Check to see how the design affects this. I suspect that for example exhaust exit through a stern drive would be completely different than an exhaust exit through the transom. Might be wrong. I maybe saw mention of flappers for a mercruiser.

Mercruiser exhaust shutters. Exhaust flappers.

Has this boat been used in salt water?

Might want to ask a marine mechanic. Or try a boat forum. After looking under the hood of a modern large outboard. I thought this was more complex than a modern car. Your symptom is so clear cut they should be able to really help.

I know nothing about this type of engine and set up. Still a quick test I might try. Disable ignition. Take air filter off. Obstruct carb if possible while cranking with the palm of your hand. On dry land you will feel suction. Compare this with in the water. I would use my carb balancer for this test myself.

No suction and the exhaust is closed. Also on your dry land test. You stated it will start with a hose feed. Will it start with no hose feed? Starting it up with no hose feed for a short interval will not hurt anything.

That large modern outboard had so many safety features to prevent damage to the engine all I realized is without a code reader designed for it servicing it might be rough.

Decided to say screw it, and offload the boat.

Too much work, not enough reward in it.

Nice way to experience the 2 happiest days of boat ownership without the middle process. [thumbs up]

Does he get it? ;)

That's the boating creed.....:D

Yep, the day you buy it, and the day you sell it.

That's probably true with 100% of all boats

From the link kmaysob posted -


It sounds like there may be a problem with the exhaust shutters in the exhaust Y pipe. The shutters are designed to keep water from back washing into the exhaust manifolds and engine under certain circumstances. If one or both have come loose or broken off they could be partially blocking the exhaust.

The transom assembly for the outdrive has two exhaust relief holes which are barely under the water when the boat is completely in the water They are there to provide exhaust relief at idle since the engine isn't producing enough exhaust pressure to push the exhaust out through the prop. Without exhaust relief the exhaust backs up into the cylinders which keeps fresh oxygen from getting into the cylinders. Without oxygen the fuel in the cylinders can't burn.

If one or both exhaust shutters have come loose they may be partially blocking the exhaust. Out of the water there is no back pressure on the exhaust, so as long as the shutters aren't blocking the exhaust off completely it will crank. When running with the drive only partially submerged it's the same deal. Once you back the boat completely in the water the lower part of the exhaust fills with water. When spinning the engine over with the starter there is not enough exhaust pressure to overcome this, so the engine won't start.

This issue is usually related to the engine running hot, which cooks the exhaust shutters. It can also come from age, corrosion or just bad luck. This may not be the problem at all, but it certainly sounds like it and is easy to check. To check the shutters you'll have to remove the exhaust risers from the top of the exhaust manifolds along with the exhaust elbows and tubes between the risers and Y pipe. The shutters will be in the top of the Y pipe on each side, circled in red in the picture below. If they are missing they will be found in the bottom of the Y pipe. You can find a flexible grabber type tool at most auto parts stores or possibly a hardware store to assist in getting the pieces out.
http://www.justanswer.com/boat/2xvs7-boat-wont-start-water-starts-driveway-454-mercruiser.html