Yanmar 6LP Water Exhaust Not Exiting Overboard

[Fast Tack]

Hello,
I have a pair of Yanmar 6 LP 's connected to my Mercruiser Sterndrives. Normally when I start them up the exhauset and water are seen coming from the stern drives with the bubbling of water from them.

The other day that did not happen and the exhaust was coming from the engine room and somewhere from the engine. Somehow the exhaust and water are being restricted from entering the exhaust ports of the sterndrives .

Any idea what could be causing the restriction and the complexity of fixing it ?

Thank You all for any help with this !

[Shrew]

I've owned a boat with a 6LPA-STp2 for about 8 years. However that should be irrelevant. Raw water works relatively the same everywhere.

Follow the path. Hint: Everywhere there's raw water, there's a zinc.

Seacock -> Strainer -> Raw Water Pump -> Fuel Cooler -> Engine Oil Cooler -> Intercooler -> Heat Exchanger -> Exhaust Elbow -> Lifter Muffler -> Exhaust Port.

Water inside the bilge sounds like a hose has failed somewhere in the path.

[skipperpete]

It might be a restriction in the mixer or you could have had a partial loss of raw water flow and melted a hole in the aqualock if you have one. More likely is the possibility that the clamp that holds the heavy mixer to the turbo has corroded and allowed the flanges to separate, either way , you need to get into that compartment with a good flashlight and closely inspect the entire exhaust from turbo to sterndrive, then wash down the area where the raw water/ exhaust leak occurred, it isn’t good to leave a salt crust on anything in the engine compartment.

[Fast Tack]

Many Thanks, Will do