947 tuned pipe gets hot, little to no water out of cooling sys indicator

[Boyd12]

I have a 99 XP 947 that I picked up recently. The engine was wasted by the previous owner so I rebuilt it. The engine runs well, but the issue is
1. the tuned pipe gets very hot after a couple minutes of operation and
2. hardly any water exits on the left side of the hull.
The cylinder and head just get warm, not hot.
The pressure regulator on the muffler leaked, so I installed an o ring to see if that would fix it. It didnt. I replaced the water regulator housing, it still leaks, and still hardly any water coming out of the left side of the hull.
I blew out all of the coolant lines during the process and the engine passed the leak down tests. There is no evidence of water in the combustion chambers.
According to the diagram, most of the water to the tuned pipe comes through the head/cylinder and exhaust manifold, then to the pipe. If the engine is cool, then it is getting water. if the engine is getting water, then shouldnt the pipe be getting plenty of water? Some water is directed by the pressure regulator, but it would seem most of the cooling is done by water from the engine itself.
Any suggestions would be appreciated!

 

[1of500]

I've see sand cakes in cooling passages. Also salt can do a number on them

 

[Boyd12]

I've see sand cakes in cooling passages. Also salt can do a number on them

Do you mean in the head, cylinder, manifold areas?

 

[Boyd12]

I just thought of something. I ran it on the garden hose, which runs water through the cooling system backwards. When I did, the pipe was cool, and water was spraying out of the hull, but the engine was hot.
I didnt have much water pressure going through the hose, so maybe that was the cause. I have no idea.

 

[Boyd12]

Is the water pressure regulator entirely or primarily for performance not cooling? It appears by the diagram that the majority of the water flowing through the pipe comes through the engine, not the valve.
Since that is the case, what would cause the engine to be warm (water is getting to it) and the pipe get hot, with NO water to flow out of the side of the hull?
Since there is water in the engine, what would stop it from getting to the pipe and out of the side of the hull? I blew out the lines and the engine was dipped and checked before assembly.

 

[1of500]

My guess yet again is a clogged up pipe

 

[Boyd12]

My guess yet again is a clogged up pipe

Thank you for your reply. Your first post "I've see sand cakes in cooling passages" did not mention the pipe. I asked for clarification and received none. Now I know what you meant. Again, thank you!

 

[mikidymac]

So the pipe has a water jacket that keeps it cool and that can definitely get clogged with sand and debris.

The water regulator sprays water into the pipe in the exhaust stream that cools the inside of the pipe changing the sonic wave for performance but also keeping the water box and couplings cool. If you are melting the rubber couplers after the pipe it’s the water regulator, if the pipe itself it getting too hot it’s the water jacket of the pipe.

 

[Boyd12]

So the pipe has a water jacket that keeps it cool and that can definitely get clogged with sand and debris.

The water regulator sprays water into the pipe in the exhaust stream that cools the inside of the pipe changing the sonic wave for performance but also keeping the water box and couplings cool. If you are melting the rubber couplers after the pipe it’s the water regulator, if the pipe itself it getting too hot it’s the water jacket of the pipe.

Thank you!
It also has a Group K head modification which i have disconnected for diagnostic purposes. It seems to be overkill to me. Would it be OK to remove the hoses and just cap the plugs in the head?

 

[mikidymac]

No. If it has the Group K mod then something else has been done by Group K and it needs the extra cooling. Your best bet is to give them a call and ask about cooling flow and routing.

 

[Grim]

I have a 99 XP 947 that I picked up recently. The engine was wasted by the previous owner so I rebuilt it. The engine runs well, but the issue is
1. the tuned pipe gets very hot after a couple minutes of operation and
2. hardly any water exits on the left side of the hull.
The cylinder and head just get warm, not hot.
The pressure regulator on the muffler leaked, so I installed an o ring to see if that would fix it. It didnt. I replaced the water regulator housing, it still leaks, and still hardly any water coming out of the left side of the hull.
I blew out all of the coolant lines during the process and the engine passed the leak down tests. There is no evidence of water in the combustion chambers.
According to the diagram, most of the water to the tuned pipe comes through the head/cylinder and exhaust manifold, then to the pipe. If the engine is cool, then it is getting water. if the engine is getting water, then shouldnt the pipe be getting plenty of water? Some water is directed by the pressure regulator, but it would seem most of the cooling is done by water from the engine itself.
Any suggestions would be appreciated!

On a off topic, where did you get the diagram of the water flow? I have been looking for these type diagrams on my 98 GTX LTD, not sure where to get them.

 

[Boyd12]

On a off topic, where did you get the diagram of the water flow? I have been looking for these type diagrams on my 98 GTX LTD, not sure where to get them.

Sorry to take so long to respond, I just saw your post! It is out of the Sea Doo manual.