Catalytic Converters on JetBoats

[Dean P]

Does water flow thru catalytic converters? I know they're meant to diffuse fumes but should water be present. Is water pumped thru these?

 

[tdonoughue]

I can't say definitively, but I don't think so (and I hope not). Catalytic converter uses a catalyst along with the heat from the exhaust to (basically) combust the rest of the exhaust that didn't fully combust in the cylinder, thus making a cleaner exhaust (and adding to backpressure, which is why they impede performance). Were it to have water in it, I don't think it would work...

 

[Dean P]

I can't say definitively, but I don't think so (and I hope not). Catalytic converter uses a catalyst along with the heat from the exhaust to (basically) combust the rest of the exhaust that didn't fully combust in the cylinder, thus making a cleaner exhaust (and adding to backpressure, which is why they impede performance). Were it to have water in it, I don't think it would work...

I agree with you. Looking at it again water does not flow thru but is definitely present on the exiting side. See picture 1.
I also notice water spitting out in this location (hence this post). Upon further review at looking at the CC I noticed there were bolts missing and several were loose (on both engines - don't think this is good). See picture 2.
Don't understand why bolts are loose. My guess is they were never lock-tighted???
I'm thinking sand got in there and could be blocking things? Does that make sense?

Picture 1:


Picture 2:

 

[tdonoughue]

Well, water spitting out does not sound good... I don't have a Chap, but I know things were loose when delivered on my Yammy (I went through and tightened everything and put antiseize on everything--that turned out to be a good move). So that may just be a regular maintenance item. Normally at that location you will not find nylon lock washers, because the heat of the exhaust would destroy them. Might want to check the temp requirements on the Locktite before applying to make sure you don't have the same issue.

Very common to have the cooling water exiting the exhaust. Cools the exhaust and gets rid of the exhaust water. Of course, anywhere in the cooling line can get clogged if you suck up some sand or don't flush when in salt. Why do you think things might be blocked? Because of the leak?

 

[Dean P]

Well, water spitting out does not sound good... I don't have a Chap, but I know things were loose when delivered on my Yammy (I went through and tightened everything and put antiseize on everything--that turned out to be a good move). So that may just be a regular maintenance item. Normally at that location you will not find nylon lock washers, because the heat of the exhaust would destroy them. Might want to check the temp requirements on the Locktite before applying to make sure you don't have the same issue.

Very common to have the cooling water exiting the exhaust. Cools the exhaust and gets rid of the exhaust water. Of course, anywhere in the cooling line can get clogged if you suck up some sand or don't flush when in salt. Why do you think things might be blocked? Because of the leak?

My last outing, I skimmed and touch over a sandbar (may have sucked in some sand) and a couple weeks ago beached the boat and powered off. Not a bright move , as this probably pushed sand right into the pumps. When I powered up the other day, there was no power. I opened the hatch and notice water spitting from that area in the picture. That's when I noticed bolts missing and many loose. Tightening the bolts did not solve the issue. I'm thinking sand may be trapped in the adjoining pieces. Just guessing, not really sure.

 

[swatski]

My last outing, I skimmed and touch over a sandbar (may have sucked in some sand) and a couple weeks ago beached the boat and powered off. Not a bright move , as this probably pushed sand right into the pumps. When I powered up the other day, there was no power. I opened the hatch and notice water spitting from that area in the picture. That's when I noticed bolts missing and many loose. Tightening the bolts did not solve the issue. I'm thinking sand may be trapped in the adjoining pieces. Just guessing, not really sure.

I'm pretty sure the cats would be cooled along with the exhaust inside the boat.
But the only way sand could cause trouble would be by obstruction, and that leading to an overheat. Any signs of overheat?
Otherwise it could just be corrosion/loose bolts, not much to do with sitting on a sand dune. I think.

--

 

[Dean P]

I'm pretty sure the cats would be cooled along with the exhaust inside the boat.
But the only way sand could cause trouble would be by obstruction, and that leading to an overheat. Any signs of overheat?
Otherwise it could just be corrosion/loose bolts, not much to do with sitting on a sand dune. I think.

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I kept looking at the temps. All was good, gauge never moved.

I posted pictures of my O2 sensors and I asked what does all the crap on the sensor look like. I believe it was sand. I need to pull the O2 sensors now and see what they look like. I bet they're sandy. This is crazy but interesting.

I scheduled an appointment to drive to the dealer in Orlando on Friday. Too many weird things happening that I believe are over my head. Hopefully the "pros" can figure this out.

 

[tdonoughue]

Do you flush your engines after each outing with Salt Away or something like that? I have sucked up a bit of sand in my time, but never killed an engine with it. However, if you have corrosion from salt in there that can trap the sand...

 

[Dean P]

Do you flush your engines after each outing with Salt Away or something like that? I have sucked up a bit of sand in my time, but never killed an engine with it. However, if you have corrosion from salt in there that can trap the sand...

Yes, I flush after each use. Always, ask my neighbors. I do not use any additives, never have. These engines have their own cooling system which means the engine is protected from salt water. I'm just rinsing everything to do with the exhaust. I'm gonna pull the sensors tomorrow and those small hoses I pointed to and see what they look like.

I have read that when CC (in cars) go bad, all power is lost. I have no top end at all right now. Stinks...

 

[tdonoughue]

No top end is bad. Especially in a 2017.

Take some pictures of the sensors and hoses. Inquiring minds want to know...

 

[Dean P]

No top end is bad. Especially in a 2017.

Take some pictures of the sensors and hoses. Inquiring minds want to know...

I took the boat to the dealer on Wednesday. Figured I would let them deal with it. I had some other items I needed to be looked at and figured while still under warranty; kill two birds with one stone type thing.

 

[rocky5]

HI Dean P,
My 4-tec has the same issue. Same water flush-spitting point from the cat. Was it just the bolts and seal or something more?
Thanks for any feedback!

Picture 2:
View attachment 97873