Water pump failure

[Spaceman]

Like many liquid cooled units air is extremely hard to remove from this system. By taking a funnel and sealing it to the system I could run the sled and see air come out over a period of time. The bleeder on the right side of the sled also will burp air. In our work area we hang the sled from the spindles and the back bumper. Lowering the rear and raising multiple times removes allot. Any air is the enemy of a pump.

 

[STAIN]

https://www.amazon.com/dp/B01BW39HJS/ref=as_li_tl?ie=UTF8&tag=Tyche-4194-im-20

 

[Spaceman]

https://www.amazon.com/dp/B01BW39HJS/ref=as_li_tl?ie=UTF8&tag=Tyche-4194-im-20

Awesome. Thanks for finding that.

 

[stgdz]

It wouldn't surprise me at all if the impeller manufacturing has been outsourced by Yamaha to China since 2017 and are using inferior materials.

Wouldn't we see a lot of waverunner and yxz failures then?

 

[twyztid]

Wouldn't we see a lot of waverunner and yxz failures then?

There ARE a lot of failures in the SXS's. That is WHY Dasa Racing is making the billet impellers. It isn't because of failures in the sleds. It just happens that the engine is the same so the water pump that they make works for our sleds as well.

 

[Simplespeed]

The question was … Lol. Is the cooling of the turbo causing the cavitation in the system thats taking out the water pump propeller ??? The loose hose clamps should be leaking antifreeze if system is under pressure at all ?

 

[earthling]

The question was … Lol. Is the cooling of the turbo causing the cavitation in the system thats taking out the water pump propeller ??? The loose hose clamps should be leaking antifreeze if system is under pressure at all ?

Since looking into this a bit, it sort of bugs me that the gurgle is there at all. gurgle implies air? not sure what else causes the noise. The convection (thermosiphon) used to cool the turbo should not be 'creating' air, as I suspect that the coolant should be below its boiling point unless it is flash boiling as it touches the hot impeller housing or wherever it flows. If this is the case, the only cure is to not use the convection cooling? (question not a statement) and/or add a secondary circulation pump on a timer, or as some have suggested, add some sort of auto-bleed valve to the system. dunno. A properly working thermosiphon should be circulating pure fluid and probably wouldn't make any noise.

 

[KnappAttack]

Since looking into this a bit, it sort of bugs me that the gurgle is there at all. gurgle implies air? not sure what else causes the noise. The convection (thermosiphon) used to cool the turbo should not be 'creating' air, as I suspect that the coolant should be below its boiling point unless it is flash boiling as it touches the hot impeller housing or wherever it flows. If this is the case, the only cure is to not use the convection cooling? (question not a statement) and/or add a secondary circulation pump on a timer, or as some have suggested, add some sort of auto-bleed valve to the system. dunno. A properly working thermosiphon should be circulating pure fluid and probably wouldn't make any noise.

The gurgle is boiling of the coolant coming out of the turbo from the extreme heat. Evidently people just shut them down after a hard run rather then letting them cool down before shutting off....


Turbo on any engine should be run easy and idled before shutting it off, not only does it preventing the oil from coking and taking the turbo out over time, it also prevents the coolant in the turbo from boiling and making the gurgling noises. Gurgling is not a good thing, it tells you you didn't let it cool down enough prior to shutting it down. Its simple turbo 101.

 

[Simplespeed]

I agree and it is just more likely that the cavitation and Air is caused from cooling the turbo and forever reason the air is getting in ( we know this should not be happening ) but the system has a flaw.. Now where is it and why???

 

[Simplespeed]

The gurgle is boiling of the coolant coming out of the turbo from the extreme heat. Evidently people just shut them down after a hard run rather then letting them cool down before shutting off....


Turbo on any engine should be run easy and idled before shutting it off, not only does it preventing the oil from coking and taking the turbo out over time, it also prevents the coolant in the turbo from boiling and making the gurgling noises. Gurgling is not a good thing, it tells you you didn't let it cool down enough prior to shutting it down. Its simple turbo 101.

Ok Mike, thats kind of what I was thinking also ..

 

[NYTurbo]

What makes u think the system has a flaw ?

 

[stgdz]

I thought Yamaha had a feature on the 998 that made a turbo timer unnecessary or the technique of running a turbo timer without one.

 

[earthling]

The gurgle is boiling of the coolant coming out of the turbo from the extreme heat. Evidently people just shut them down after a hard run rather then letting them cool down before shutting off....


Turbo on any engine should be run easy and idled before shutting it off, not only does it preventing the oil from coking and taking the turbo out over time, it also prevents the coolant in the turbo from boiling and making the gurgling noises. Gurgling is not a good thing, it tells you you didn't let it cool down enough prior to shutting it down. Its simple turbo 101.

Thinking this through and I agree with you WRT cooling the turbo post run.

But.. This was by design. Yamaha actually brags about the vapor tank/convection cooling aspect of the system

I guess I have to go out in the garage and look at the actual system, the parts fiche doesn't really tell the story (at least so I understand it).

 

[Simplespeed]

What makes u think the system has a flaw ?

Maybe flaw would be wrong description, how about we refer to it as a design that is need of improvements to again prevent water pump problems..

 

[earthling]

Maybe flaw would be wrong description, how about we refer to it as a design that is need of improvements to again prevent water pump problems..

To evaluate it as a flaw we need to understand the byproduct (measure the outcome). Ignoring the water pump for a second, if we saw a lot of turbo failures I would say the design is flawed. To know how well it is working we would need to measure the system post shutdown for flow as well as input/output temperature on each side of the turbo. If it is indeed causing air to enter into the system then that is also a flaw. Right now the only way we know it is working is the gurgling which implies that the coolant is boiling and maybe that is all in how the vapor tank works (which I see in the fiche but have not looked at).