bad engines or me?

caverun man

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Jul 5, 2007
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:( I have thrown a rod thought two engines. The first was a 2002 Rinker with a 96 hours . The engine is a 5.7 300 hp brovo 3. That time my top blowed back so I pulled back on the gas real quick and bang rod thought the block. This time it was the same motor size in a 250 Rinker Cabin cuisers with 390 hours but this time i had to go out of forward to revese real quickly to avoid another boat come at me. No damage to the outdrive but a rod out the oil pan. Would going from forward to revese quickly blow a engine.
 

tommays

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Jul 4, 2004
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Re: bad engines or me?

What kind of RPM are you running these motors at :confused:

While they will spin 4800 RPM it will be a reduced life


Tommays
 

caverun man

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Re: bad engines or me?

The first one had 96 hours with 42 at idle I babyed it around . The second one I ran a little harder it ran at about 30 miles a hour 3500 rpm. Had no problems until I pulled it in reverse hard out of forward. I did pull it hard in to reverse out of forward. Happen quickly so I think it blow it in reverse. Top speed was about 40 never paid much to the rpms.
 

tommays

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6,768
Re: bad engines or me?

sudden stops like your second one can allow the motor to suck in water from the exaust manifolds

This will pretty much kill a motor

Tommays
 

caverun man

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Re: bad engines or me?

It killed it aright out of warrent by a mouth or so its me not bad motors than looks like it would have torn somethink up in the outdrive but no damage that we can find.
 

Bondo

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Apr 17, 2002
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70,470
Re: bad engines or me?

so its me not bad motors

Ayuh,...........

I think that pretty much sums it Up.................

Chopping the throttle causes the Backwash to travel Up the Exhaust,+ when the water gets to a cylinder,.......
It Doesn't Compress like Air,........... Somethings Got to Give,.......
And in your Cases,.........
It's been the Rods................
 

caverun man

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Jul 5, 2007
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Re: bad engines or me?

I have full coverage ins will it cover the repair or am I on my own?
 

Mischief Managed

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Dec 6, 2005
Messages
1,928
Re: bad engines or me?

It killed it aright out of warrent by a mouth or so its me not bad motors than looks like it would have torn somethink up in the outdrive but no damage that we can find.

Warranty would not have covered water ingestion damage anyway. Straight out of the "what is not covered by the Mercruiser warranty" section:

"water entering the engine through the fuel intake, air intake
or exhaust system"

In both cases it's a safe bet that water came up through your exhaust system, through an open exhaust valve, and completely stopped a piston on it's compression stroke. The inertia of the rest of the recriprocating mass in your engine made the connecting rod for the stopped piston break free and find a new place to go, a place it was not meant to.
 
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