How does one hydro lock a IO?

hostage · Mar 19, 2013

I was looking through craigslist and I saw a 2002 deckboat w/ a 4.3L EFI for $3k. Granted it is a Tahoe, thought the price was very low. I did see it needs work and TLC.

I call up the dealer and he says the engine is hydro locked and the gelcoat is chipping. I know what hydrolock means, though I am curious how exactly one is able to do this in an IO? I am wondering if the boat was swamped or can a cracked block cause this?

After hearing the issues I am no longer interested: TAHOE DECK BOAT 02

-Hostage

Oshkosh1 · Mar 19, 2013

Re: How does one hydro lock a IO?

Several ways...those you mentioned also a bad/missing exhaust shutter is a big culprit.

hostage · Mar 19, 2013

Re: How does one hydro lock a IO?

It just seems odd, I have heard of cars going through huge puddle becoming hydro locked. Just the first time I have heard of a boat doing this.

Silvertip · Mar 19, 2013

Re: How does one hydro lock a IO?

Whenever there is a path from the water jacket to the cylinder bore you can hydrolock an engine. That is also caused by reversion where valve overlap can draw cooling water from the exhaust back into a cylinder. Folks who think they can hot rod a marine engine with a wild cam find out about reversion unless they do some serious exhaust design work to prevent the issue. Cracked head, cracked block, incorrectly assembled GM engine where sealant is not used on head bolts, are all likely causes.

h2odick · Mar 19, 2013

Re: How does one hydro lock a IO?

Yikes! Somebody didn't take care of that thing! 2002 - doesn't look it. Not to mention, its sitting on a glastron trailer, obviously not bunked for that boat properly, look at the hull sitting on top of the fender in the picture..

agallant80 · Mar 19, 2013

Re: How does one hydro lock a IO?

Run!

tpenfield · Mar 19, 2013

Re: How does one hydro lock a IO?

Water getting into the lower end of the exhaust can cause a hydro-lock due to a process called 'reversion' which occurs at the top of the exhaust stroke. Also water from a crack or flaw in the intake manifold or cylinder head can cause it as well.

No need to swamp the boat . .

04fxdwgi · Mar 20, 2013

Re: How does one hydro lock a IO?

Oshkosh1 said:
Several ways...those you mentioned also a bad/missing exhaust shutter is a big culprit.

Surely that can't be.

In another post some long time posters are stating shutters are a waste of time and not needed.

Go figure....

spdracr39 · Mar 20, 2013

Re: How does one hydro lock a IO?

In the background is another neglected looking boat. I think I would stay away from this dealer.

Toddavid · Mar 20, 2013

Re: How does one hydro lock a IO?

Leaking exhaust manifolds or risers, which are water cooled on a boat. Not specific to I/O config.

rallyart · Mar 20, 2013

Re: How does one hydro lock a IO?

Blown head gasket or a cracked block can hydro lock and engine. As can putting it underwater.
Sounds like a boat the dealer is stuck with and is not worth their time on so they want to dump it. If it's their business to know about boats and they think it should be dumped, maybe you should think that too.

H20Rat · Mar 20, 2013

Re: How does one hydro lock a IO?

that boat is a wreck for that price... don't even think about it.

sweet addiction · Mar 20, 2013

Re: How does one hydro lock a IO?

smokingcrater said:
that boat is a wreck for that price... don't even think about it.

^^^^^YUP!!! That boat must have been previously owned by some 18 year old with daddy's checkbook and no respect. That boat is a friggin train wreck at best!

sweet addiction · Mar 20, 2013

Re: How does one hydro lock a IO?

h2odick said:
Not to mention, its sitting on a glastron trailer, obviously not bunked for that boat properly, look at the hull sitting on top of the fender in the picture..

I concur...What a mess!!! I feel sorry for the fool who buys this bastardized wreck. Unless they buy it for MUCH less than the posted price and actually know what they are buying and know how to fix it ALL.

Idlespeedonly · Mar 20, 2013

Re: How does one hydro lock a IO?

Also shutting them down while on plane can do it.

frantically relaxing · Mar 20, 2013

Re: How does one hydro lock a IO?

Here's it's twin with a 5.0...

If the engine is just locked and not busted because it's locked, for $2500 that boat might be worth doing a little work. Would be nice to see the inside. Probably a storm victim.

haulnazz15 · Mar 20, 2013

Re: How does one hydro lock a IO?

Idlespeedonly said:
Also shutting them down while on plane can do it.

That's not necessarily true. The only thing that would cause that to happen is if the wake catches up to the stern of the boat AND there are no exhaust shutters in place.

Cleansweep13 · Mar 20, 2013

Re: How does one hydro lock a IO?

I actually hydro locked my boat this weekend at the lake. I was looking at the emergency shut down switch and wondered if it still worked. I don't know what I was thinking. I pulled the switch and it brought the boat to an abrupt stop turning over the engine. After I stopped, I tried to restart the boat and it sounded like a thrown rod and the boat would not crank over. I had to paddle back to dock. At the dock I tried to crank over by hand and I thought I heard liquid in the cyclinder. I immediately removed the spark plugs turned the engine over acouple times and of course water came squirting out. Put new plugs in and started engine to make sure any water in the cyclinders would be evaporated. It was scarry, I thought the engine was blown. Engine ran fine after that. I did all this in about two hours since I did not want to take any chances with rust. There were no signs of water in the oil the next day and it is running fince, however draining oil today just as a precaution. I'm just glad I diagnosed problem because a lot of people would have drove home and the engine probably would have been ruined.

Bondo · Mar 20, 2013

Re: How does one hydro lock a IO?

Ayuh,.... The Most common cause of Hydro-lock I've found in boats that have been Sittin' for awhile is,...

Rain water down through rotten motorboxes, Right down the throat of the Carb.....

90stingray · Mar 20, 2013

Re: How does one hydro lock a IO?

Look at the sellers location... its probably the remains from hurricane sandy.

How does one hydro lock a IO?

Lieutenant

Ensign

Lieutenant

Supreme Mariner

Petty Officer 2nd Class

Commander

Moderator

Senior Chief Petty Officer

Lieutenant Junior Grade

Petty Officer 2nd Class

Lieutenant Junior Grade

Vice Admiral

Petty Officer 1st Class

Petty Officer 1st Class

Senior Chief Petty Officer

Senior Chief Petty Officer

Captain

Recruit

Moderator

Lieutenant Junior Grade