Flightcraft to the rescue!!

[Rusty]

Originally Posted by NHBUOY

200 degrees was the temperature of the block. The catalysts are downstream in the exhaust. The cats will get exponentially hotter than the block.

Understandably Cats need to be hot to convert harmful pollutants into less harmful emissions.

I don't have a boat that is powered by a motor so I'm sort of in the dark about the engine safety features in newer boats. I would think that there would be some sort of warning light or sound that would tell the boat operator that the engine is reaching a dangerous and damaging temperature. To just see smoke coming from the engine compartment after it has already done some damage doesn't seem right.

[trigger finger]

I have bought two Cobalts from East Coast and Goodhue, as far as the purchasing experience it was great both times, a very good purchase price both times and no, I mean no pressure either time.
We have kept both boats at Goodhue and Hawkins first one valet the second one in a slip. I could not ask for a better place to have our boat at, they make sure that we have fun and enjoy the lake and do what ever they can to make that possible. They do a great job at making my wife and I feel like we are their very best customer and actually make us feel like we are part of their family. But to be honest I believe they do that with all ther customers, now that's customer service. Their service dept is second to none, they do quality work with a value that is well worth the price of the job. all the people that work there learn your name and go out of there way to say hi. I love good customer service and I love Goodhue and Hawkins and East Coast Flightcraft.

[Dave R]

Originally Posted by Rusty

Understandably Cats need to be hot to convert harmful pollutants into less harmful emissions.

I don't have a boat that is powered by a motor so I'm sort of in the dark about the engine safety features in newer boats. I would think that there would be some sort of warning light or sound that would tell the boat operator that the engine is reaching a dangerous and damaging temperature. To just see smoke coming from the engine compartment after it has already done some damage doesn't seem right.

There's a temperature gauge and an audio alarm for overheating. If the engine is being pushed hard when the supply is interrupted, the rubber hoses in the wet exhaust system can get hot enough to melt and smoke (without actually failing) before the alarm goes off. That's what typically causes the smoke. The hose has to be marine-rated (typically SAE J2006 standard) which defines temperature resistance and flammability, among other things, so the chances of a fire from this situation are not as bad as you'd think.

Another cause of smoke might be the engine's serpentine belt heating up due to a stalled water pump pulley.

I'm surprised that the manifolds needed replacement from a single overheat situation. Non-catalyst manifolds usually survive that kind of abuse without issues and the innards of all catalytic converters can easily withstand absurdly high temperatures since they require them to operate. I wonder if they were swapped for purely cosmetic reasons. Malibu puts a lot of "bling" on their boats, so perhaps the engines are dressed up as well.

[Rusty]

Originally Posted by Dave R

There's a temperature gauge and an audio alarm for overheating. If the engine is being pushed hard when the supply is interrupted, the rubber hoses in the wet exhaust system can get hot enough to melt and smoke (without actually failing) before the alarm goes off. That's what typically causes the smoke. The hose has to be marine-rated (typically SAE J2006 standard) which defines temperature resistance and flammability, among other things, so the chances of a fire from this situation are not as bad as you'd think.

Another cause of smoke might be the engine's serpentine belt heating up due to a stalled water pump pulley.

I'm surprised that the manifolds needed replacement from a single overheat situation. Non-catalyst manifolds usually survive that kind of abuse without issues and the innards of all catalytic converters can easily withstand absurdly high temperatures since they require them to operate. I wonder if they were swapped for purely cosmetic reasons. Malibu puts a lot of "bling" on their boats, so perhaps the engines are dressed up as well.

Thanks for the info.

I'm with you about the manifolds, and this is why I asked the question about alarm systems. If they got that hot and had to be replaced, then the alarm system must have gone off prior to destroying them and the engine should have been shut down somehow. I'm going with your theory about replacing them for cosmetic reasons only.

[Baja Guy]

Catalysts getting hot enough to smoke ought to be changed. It sounds as if over temp exhaust caused it. That much heat can cause the internal cats themselves to change, or it could change the shape or metal of the external cases.
I'm glad you were well treated. Boats cost a lot of money, they have warranties for the things that happen while covered.