Water in the Cylinders

smvorca350z

A friend of mine has a Sea Ray 280 with 496 B3 in it and twice it has hydro-locked with water getting into the front 2 cylinders on the port side. Each time he's removed the plugs, dried off the plugs and it's good to go.  

Anyone know why this would happen and how to prevent it from happening again other than to bu a Rinker

jme097

I would say it wouldn't be specific to the brand of boat as it would be to the Merc drive/engine set up. But wouldnt flappers stop this?

Cableguy Greg

I would be checking the flappers if it happened twice. Sounds like they need replaced.

randy56

The springs on thse flapers get weak. or break

craigswardmtb

He may need taller risers. Early 2000s I believe my 496s came with shorter risers. Check flappers too. 

Michael T

Flappers, risers and is he backing down the launch ramp fast?

diggin2day1

This just happened to me when I had my 270 launched... Mechanic pulled plugs, dried her out and was good to go. Scared the crap out of me when it happened(didn't know what it was, never experienced it before). So my first "run" of the season was behind a SeaTow boat from the launch ramp to my slip... Not the best way to start the season. 

zaverin1

Flaps first.
risers second. Any moded or performance risers would put a regular  boat at risk.

diggin2day1

Wow Alswagg, that is exactly what the mechanic said to me and I thought it sounded kind of crazy... Glad to hear it from someone else too!

MarkB

Al knows his stuff!

smvorca350z

Al - Is there any way to prevent it?

212rowboat

in addition to that^, make sure your ignition base timing is right.... dieseling can also be caused by bad timing- and anytime that engine turns the wrong direction you've created a huge vacuum pulling water right out of the risers, back into the manifold, and into the cylinder ON THE CYLINDER that is using it's exhaust valve to make said vacuum.  

Michael T

....no one has modified the risers to reduce their height, right? or "chipped" the AFR map, right? The 496 is a marinized truck engine. At one time they had timing and valve overlap issues but that should not affect your model year - as long as no one has scre*ed with the timing!

Youllbefine

Does this boat have Corsa exhaust?  Lack of exhaust back pressure has an impact on water reversion.

Youllbefine

Cylinder mis-fire will do it too.