[Nelson_hotwheels]

So my wife took our spark out in a storm yesterday and ran it up on ground on an island, It sucked up a lot of rocks and completely jammed the impeller. She tried to drive it back to land and the check engine light came on and said it was overheating and it started beeping, mind you she was holding it to the bar and it wasn't moving because it was jammed. Luckly a boat passing by seen her and towed her to shore, I'm just wondering how much damage she could have caused on her adventure. the prop looks ruined and so is the wear ring, Any chance it could have done engine damage too? I also read in the manual that there is a line that is supposed to be blocked off if it gets towed but that never got done either. there was a lot of water in the engine compartment, it drained for at least 2 mins straight.

 

[stuckmoto]

If you damaged the wear ring too bad(blew a hole in it) you probably couldn't get enough pressure to the manifold and muffler to cool it hence the overheat alarm. If she was towed over 10mph you could very well have water in the motor. Have you checked the dipstick for milky oil? If so...you need to pull the top deck, get the plugs out and crank it over in the drowned mode ASAP. If no water if coming out you might be lucky, if not, you need to do a bunch of oil changes. If this too big of a job then call the dealer right away. Rust is already beginning to set so the clock is ticking.

 

[Patrick]

If you couldn't get enough pressure from the pump to supply water to the exhaust(due to the broken wear ring), you probably didn't get enough pressure from towing it either. But check just to make sure, and replace your impeller and wear ring


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[Nelson_hotwheels]

It would still start and run fine after it was towed, just wouldn't move and it was making a grinding sound and viberating bad, pretty sure the wear ring has a hole in it also, going to take it apart tonight and check oil and plugs. I'm pretty sure they would not have got over 10 mph, The boat towing her almost flipped from the waves, She should not have been on the water at all

 

[ScottFL]

She is grounded from the spark for now on! Hopefully a new wear ring and impellor gets you back in the water.

 

[Nelson_hotwheels]

yes she is grounded, lol, I'm going to order a solas impeller and new wear ring tonight, fingers crossed that's all that's damaged.

 

[kennetht]

If you damaged the wear ring too bad(blew a hole in it) you probably couldn't get enough pressure to the manifold and muffler to cool

i have a pretty good idea of the purpose of a wear ring, but before I sound like an idiot, can you guys clarify what purpose a wear ring has on a jetski? what does a wear ring have to do with cooling the engine?

Thanks

 

[Cormacs]

The wear ring really has nothing to do with cooling, directly anyways. The wear ring is there as a sacrificial item to protect the impeller. Instead of the impeller being housed in a solid housing it's placed in a plastic wear ring. That way if something gets in between the impeller and the wear ring the ring will break and hopefully save the impeller. Now for cooling. The exhaust is cooled by thrust water. The thrust that the impeller makes is diverted to go through the exhaust for cooling. Now if the wear ring is busted, there is no thrust causing no cooling. Now this creates a double edged sword since you are revving higher to move because you aren't making as much thrust. The higher revving engine makes more exhaust heat. Now you have no diverted thrust to cool the exhaust and a hotter running engine. That's why they usually overheat with a destroyed wear ring.


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[Nelson_hotwheels]

well my wear ring didnt have a hole through it but it is scared pretty bad, The impeller is destroyed and so is the impeller housing. I wish the wear ring gave out, not getting a metal one anytime soon.

 

[Nelson_hotwheels]

also, there was 3 rocks jammed in the impeller. I had to use a hammer to get 1 of them out. Good news is there is not any water in the oil from towing!!

 

[kennetht]

Now for cooling. The exhaust is cooled by thrust water. The thrust that the impeller makes is diverted to go through the exhaust for cooling. Now if the wear ring is busted, there is no thrust causing no cooling. Now this creates a double edged sword since you are revving higher to move because you aren't making as much thrust. The higher revving engine makes more exhaust heat. Now you have no diverted thrust to cool the exhaust and a hotter running engine. That's why they usually overheat with a destroyed wear ring.

I see, that would make sense. Where is the water intake at for the exhaust cooling? I know our skis are liquid cooled, I thought all cooling for the ski was done using the closed loop cooling system, as well as the heat transfer grate that is at the bottom of the ski.

Looking at the below image (not actual image of my ski, just found this photo on the internet), the exhaust flush kit on my ski is on the left. I know when out riding on the water, the main jet thrust comes out of the jet thrust nozzle. Although, I also can see water being forced out from port #1 . What is this port for? The water that is coming out of here is coming from where?

I believe port #2 is the exhaust? Am I correct there? I know when I have my ski out of the water and am flushing the ski, water flushes out through the impeller out of the jet thrust nozzle, as well as out from port #2 . When it comes out of port #2 the water is hot, so I am assuming that is the exhaust.

 

[Cormacs]

Port 1 is the suction port for the Venturi bilge. It pulls any water out of the hull that might have gotten in. Water is diverted from the impeller to cool the exhaust which then comes out the exhaust port #2 . The engine is closed loop cooled by glycol but the exhaust is still water cooler with a water jacket and water box.


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[Cormacs]

Right above the "P" for port #1 in your diagram you can see the passage for water coming from the impeller leading into the hull to cool the exhaust.

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[kennetht]

Port 1 is the suction port for the Venturi bilge. It pulls any water out of the hull that might have gotten in.

So the only water that should be coming out of Port 1 while the ski is running is water that has gotten into the hull? I find that hard to believe. Every time we are out on the water I see my brothers ski shooting a constant flow of water out of there with strong force (especially during high speeds). Mine does exactly the same...

And what is a venturi bilge? Do our skis actually come equipped with an electronic bilge pump?

 

[Cormacs]

It's not an electronic bilge it just uses water running past that port to create a suction, the other end of that is in the hull. I don't know how you could possibly tell that there is water coming out of that port while riding since it is buried under there. But water is diverted from the jet stream through there to create suction, which pulls water out of the hull.


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[kennetht]

It's not an electronic bilge it just uses water running past that port to create a suction, the other end of that is in the hull. I don't know how you could possibly tell that there is water coming out of that port while riding since it is buried under there. But water is diverted from the jet stream through there to create suction, which pulls water out of the hull.

Gotcha, I understand how it works now, but I think you still have something incorrect. Next time you are out on your ski, or are able to see another spark from behind, get close and look. Make sure the ski is planing, around 15-20 mph, so the areas above the jet thrust is completely out of the water. You can see there is substantial amount of water coming out of that port #1 , and with pretty good force.

 

[Cormacs]

There will be water coming out of it to create a Venturi.


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