Hydrolock

[MaximusBoatimus]

Hey all,

Went to have to boat put in the water and found an engine to be hydrolocked.

Had it running earlier and then I guess with the muffs still pushing water it ate it all up when I shut it off. Anywho, took the plugs out, turned over the motor several times. Drained the oil, removed the manifolds and now I'm stuck with trying to get the risers off of the manifold. Boat is a 99, motor is 5.0 305, my guess is they're seized together at the gasket I've tried heat pb blaster while tightening a bolt together and rocking it.

Thanks

[mmwjr]

Is the spacers between the manifold and risers connected by studs or just the manifolds and risers? If just the later then you can try a thin paint scraper as a chisel to see if you can separate them. It may be time to replace them.

[jparsons121]

Unless you have replaced the manifold/risers recently , I wouldn’t waste effort trying to disassemble. Just replace them.

Be sure to squirt som marvel mystery oil in the cylinders ASAP. At hat will keep the rings from rusting to the cyclinders and protect the walls as well.

[MaximusBoatimus]

Originally Posted by mmwjr

Is the spacers between the manifold and risers connected by studs or just the manifolds and risers? If just the later then you can try a thin paint scraper as a chisel to see if you can separate them. It may be time to replace them.

Dunno if this helps. I purchased gaskets for both before riser and after bolts studs I would say.

[jparsons121]

It’s hard to judge by a photo, but it looks like these are due for replacement. There is rust and pitting on the mating surface and what looks to be a Rust crack on the left water jacket. Also, there appears to be rust at the bottom of the manifold, where no water should ever be. May be flash rust, but from this photo it appears to have been rusting for a longer period.

Also, although anything is possible, I’m skeptical that water from the muffs would have flooded the engine. You should have BII drives which use the engine mounted raw water pump. If the impeller is in good shape, you can’t pass water from the muffs thru it without the engine running. It may be possible that the higher pressure from the hose/muffs helped you find the underlying issue with the exhaust leaking.

When were the manifold/risers last replaced?

[mmwjr]

Hard to tell with the old gasket in place but the wall between the water jacket and exhaust passage looks to be thin from corrosion. I would replace the exhaust components.

[MaximusBoatimus]

Originally Posted by jparsons121

It’s hard to judge by a photo, but it looks like these are due for replacement. There is rust and pitting on the mating surface and what looks to be a Rust crack on the left water jacket. Also, there appears to be rust at the bottom of the manifold, where no water should ever be. May be flash rust, but from this photo it appears to have been rusting for a longer period.

Also, although anything is possible, I’m skeptical that water from the muffs would have flooded the engine. You should have BII drives which use the engine mounted raw water pump. If the impeller is in good shape, you can’t pass water from the muffs thru it without the engine running. It may be possible that the higher pressure from the hose/muffs helped you find the underlying issue with the exhaust leaking.

When were the manifold/risers last replaced?

Ready for a good laugh? Those be original, batteries are from 2013. Bought the boat and have slowly replaced individual parts. Impellers were next, after batteries carbs etc lol. Haven't been able to find ones with 3inch risers which is what I have here. I felt as though they would need to be replaced as well.

[jparsons121]

I suspected that they were old. I’m on my 4th set since ‘99. Check out the newer dry joint versions. I just put them on mine this year.