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Frogman

Water ingestion into cylinders from wake surfing

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Frogman

I have a 2002 LSV that we have owned for 10 years in central Texas. We started wake surfing last year and mid summer this noticed the engine was not running on all cylinders. Took it to the local mechanic and he said he has seen this in the past couple of years on three boats. He believes that when you wake surf and the back end of the boat sets so low in the water when you stop quickly the rubber caps on the exhaust do not shut fast enough and there is a surge of water back into the muffler which then forces it back to the engine. These are my non technical words, but I am looking at a big rebuild bill and wanted to know if anyone has had a similar issue and is there a fix to keep this from happening.

The local shop said there is a stainless steel exhaust cap that should help this from happening again. Any thoughts or guidance would be appreciated.

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JasonK

Not sure what exhaust "cap" he refers to, but I would think the turn-down exhaust tips would help. And stopping slowly.

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wakedncsu

i'm calling shenanigans. That is the whole purpose of flappers. To stop a wave surge from entering back into the motor. I dont see the force of the water pushing against the flapper beating the seal so much that you get water back. Not if the flapper is in working order anyway. I could see a ripped/cut flapper not sealing and the force of the water pushing water through. Are your flappers in good condition?

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Lance B. Johnson

Out of the years ive been on this forum and all the people wakesurfing no one that I can remember has had this issue. I think hes just got a theory. If you had water in your cylinders I would be looking at other possibilities.

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wakesetter8796

Our dealer said if you lean the boat over too far then the engine will blow up and starve for oil. Never heard of that happening though?

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tvzzz

Even if water made it past the flappers it would not make it past the exhaust pressure coming from the cylinder heads. I call bluff. Plus if enough water makes it into cylinders the result is bent connecting rods and crankshaft damage.

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tccombs

I am calling shinanigans too....

I am no expert, but here are my thoughts on it.

I really doubt that is what happened... I think you have a differant problem... Here is why

in order for that to happen,

1. the water would have to get past the flapper valve(s). I could see that happening a bit.

2. if it did get past the flapper valves, Enough water would would have to get past to completely fill the exhaust pipe(s) in order to drive the water all the way up the uphill slant into your engine. I would estimate that would have to be between quite a few gallons to fill a 3 to four inch diamiter exhaust pipe to the top... maybe 5 to 10 gallons of it.

3. In order for that to happen that water would also have to have enough pressure in it to push past the Highly pressurized exhaust gas exiting the engine.

4 Lets say the water did somehow make it to the exhaust valve which i doubt .. that valve is going to be closed until the cam opens at which time the piston is rising and continuing to pressurize. when it hits the top that valve will slam shut. So I dont think water could enter while that valve is open.

5 if by some chance a bit of water did make it into the cylidar, the firing would turn it into steam so fast that I doubt any damage could occur.

If we have an engine guys here i would be interested to know if i am wrong on this...

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Jimmypooh

Also keep in mind the exhaust is water cooled on purpose, so there is suppose to be water in there to begin with. What evidence does he have that the damage was caused by water?

I know on 2 strokes you're not suppose to run the hose water until the engine is running. Does the same go for 4 strokes? Maybe that's where the water came from?

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Lance B. Johnson

Our dealer said if you lean the boat over too far then the engine will blow up and starve for oil. Never heard of that happening though?

Haha and if you lean the boat to far over, water will come over the side and you boat might roll......I wonder which will happen first engine starve or swamp the boat?

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nyryan2001

Frogman- do you have a fresh water attachment to hook up with a hose? Do you run the boat on the hose?

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WakeGirl

I'm going to have to look it up, but I recall a member having a hydrolock issue on a sudden stop while wakeboarding. The boat had the turn down exhaust though (not STEs, these were the old turn downs) & the speculation was that the sudden stop combined with a lack of flappers in the turn downs created a perfect storm that allowed the hydrolock to occur. I'll see if I can find the topic.

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Levi900RR

My boss has an I/O that this supposedly happened to. He actually forwarded me the .pdf of the Mercrusier service bulletin with talking points for techs to describe this phenomenon to customers. I'll see if I can dig it up.

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BlastRlxi

In theory it can happen if you tried to run the boat in reverse at too great a speed. Enough water pressure and those flappers and exhauset pressure won't hold the water back. As far as it happening from surfing, I guess it's possible in theory but I wouldn't think it would be very common.

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SmoothWaterMan

Might be more likely that the high side of the engine starved for cooling water, overheated and damaged a valve, head gasket, or exhaust manifold. Cooling water will take the path of least resistance at all times, especially at lower rpm and less pressure.

pb.

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wakesetter8796

Haha and if you lean the boat to far over, water will come over the side and you boat might roll......I wonder which will happen first engine starve or swamp the boat?

Ya lol right! They also said surf gate was available for v rides.

But we have had water come over the sides sometimes, no issues.

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LS-One

I'm going to have to look it up, but I recall a member having a hydrolock issue on a sudden stop while wakeboarding. The boat had the turn down exhaust though (not STEs, these were the old turn downs) & the speculation was that the sudden stop combined with a lack of flappers in the turn downs created a perfect storm that allowed the hydrolock to occur. I'll see if I can find the topic.

Do you remember Brad his screen name was something like LSVSharks ? It happened to his 08 LSV when it was new. D Goose was with us. We heard a gurgle after we stopped and then the boat wouldn't turn over. D Goose pulled a plug and the cylinder had water in it. We pulled all the plugs and turned it over and cranked the water out.Fired back up after that.

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Frogman

Thanks for all the input. I too have had a difficult time believing that the flaps and exhaust would not keep this from occurring. The mechanic I use, has had this on two other motors lately. It was only on three of the left side cylinders as well.

My insurance company is sending out a tech to look at it as well. They had never heard of this, but the tech at the lake convinced them of it. Will let you know the outcome.

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happypappy

Thanks for all the input. I too have had a difficult time believing that the flaps and exhaust would not keep this from occurring. The mechanic I use, has had this on two other motors lately. It was only on three of the left side cylinders as well.

My insurance company is sending out a tech to look at it as well. They had never heard of this, but the tech at the lake convinced them of it. Will let you know the outcome.

I gotta think a defective flapper is better for you as far as the insurance aspect....hope it goes well! Maybe tape on a blower and tell the adjuster you have the LSA engine!! only joking.....as insurance fraud is NOThing to joke about!!

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greg2vlx

Just another thought...if the boat is listed far enough and is deep enough, not running and changing out riders water might be able to flow back up through the exhaust and into an open exhaust valve. I know inboards are different, but when I was in Korea I saw a ski boat with a honda outboard get deep enough that it hydro-locked the engine from water flowing back through the exhaust.

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shawndoggy

the off-throttle hydrolock also happened to a co-worker. He cleared the water and it never happened again, but he was forever cautious with that boat against cutting the throttle abruptly, which is why the mechanic told him it had happened.

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wakebrdr94

Our dealer said if you lean the boat over too far then the engine will blow up and starve for oil. Never heard of that happening though?

I have hear this too. Didn't indmar come out with an engine to compensate for this? I think it was called the surf 345 or something to that effect? I'll have to look it up. I thought they won an award with it

http://www.wakeboardingmag.com/news/2011/10/18/new-indmar-and-supra-engine-wins-innovation-award/

Edited by wakebrdr94

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Bill_AirJunky

I've heard of boats having problems when the flappers are missing or destroyed. I don't recall exactly what the result was though.

As for the boat leaning too far over & messing up the engine, I'd bet it has something to do with the oil pickup tube not being in the oil all the time. 4x4s & rock climbers have oil & fuel issues as a result of the extreme angles they go thru. The use of things like EFI, longer/multiple oil pickup tubes & crank scrapers help get them past the issues.

Edited by Bill_AirJunky

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Bobby Light

If it's water through exhaust without flappers, what about us folks that have STE exhaust tips with no flappers and no issues?

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Woodski

Water being drawn up the exhaust is a plausible explanation. Camshafts with significant overlap will actually draw the cooling water exiting the elbow back up in to the cylinders and causing a hydrolock condition. The cure for that are elbows that discharge the cooling system water farther downstream. This is a different situation, so here are some details that might make sense:

The probable cause if that is what is happening is the significant ballast added allows the waterline to be much higher relative to the engine or very close to the same height as the exit elbow, listing to one side probably increases those odds. Add a throttle off situation where very little gas pressure would be acting against any water upwash (which could either be lake water or engine cooling water) and I would assume on deceleration a heavily laden boat will pitch more nose down and the explanation becomes very plausible. Also, check the type of exhaust tips and flappers as many of the stainless exhaust tips only come with internal metal flappers, which do not form a complete seal, unlike the rubber flappers common on older boats and the plastic exhaust tips. If they don't form a good seal, then water will migrate up the pipe.

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happypappy

If it's water through exhaust without flappers, what about us folks that have STE exhaust tips with no flappers and no issues?

Isn't there some kinda baffle inside the STEs? or are they hollow? and just an elbow??

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