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Water pump failure


Coolant leaks from poor hose clamps causing air in system.
Impeller hits air then hits load of coolant and causes an unbalance on impeller.
We don't hear of water pump failure on the Japanese built sleds. They use constant tension hose clamps that don't leak.
 
Coolant leaks from poor hose clamps causing air in system.
Impeller hits air then hits load of coolant and causes an unbalance on impeller.
We don't hear of water pump failure on the Japanese built sleds. They use constant tension hose clamps that don't leak.
15K ON MINE SO ITS TIRED TOO.?
 
15K ON MINE SO ITS TIRED TOO.?

Mine went around 8000 miles on the sidewinder.
Nytro has over 20,000 miles with no water pump failure.
I would not guess on when yours will fail or not.
Keeping the coolant at the cold fill level when checked cold and topping up as needed and fixing coolant leaks should help.
 
Coolant leaks from poor hose clamps causing air in system.
Impeller hits air then hits load of coolant and causes an unbalance on impeller.
We don't hear of water pump failure on the Japanese built sleds. They use constant tension hose clamps that don't leak.
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.
 
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It wouldn't surprise me at all if the impeller manufacturing has been outsourced by Yamaha to China since 2017 are are using inferior materials.

I wouldn't disagree with you on that China crap.
My driveshaft said made in China right on the box.
All sidewinders leak coolant at one point or another from multiple locations at the same time letting air into the system.
 
Are we sure its from air leaking into the system ( it’s possible ) but have you listen to the noise the sled makes after you shut it down after a long hard pull… That noise is the cooling of the turbo and does that have anything to do with this issue???
 
Mine broke after a WOT run across the lake and I let off immediately I think had I rolled out of the throttle slowly it may not have snapped I thought at the time it was inertia of coolant that broke it. I had a full system and doubtful I had leaks anywhere. I installed the Dasa racing billet piece and dont recall it being too bad a job I only remember things if it was super nasty to do lol. If your wanting to fix it stock and no parts around I have my old impeller if you want it.
 
These failures are very strange to me. What in world would cause this EXCEPT just p*## poor quality from China. How does an impeller just break like that?!

I am sure you have heard people say that when you hit water fast enough its like hitting concrete. This is because fluids don't compress. The problem is that air in your system does. Cavitation may be the real culprit here but its just a guess.

Cavitation for a pump, which happens when you have air pockets (or technically any major change in density) within a fluid flow. Typically this happens at either end of the performance envelope of an impeller, when it is running slower or faster than its optimum speed, but it can also happen when you simply have air in a closed system. In our case I think the air pockets in the closed system are the culprit. The impeller is moving through a uniform volume (pressure/density) and all of a sudden there is a pocket of air, the impeller face sees this as low pressure, that bubble of low pressure air compresses until it displaces the water around it (pressure inside bubble exceeds pressure in water) and then collapses, the impeller then runs smack into the water and since water doesn't compress, and in this case it is relatively static and not flowing properly (its turbulent) it impacts the water hard. Repeat this often enough and something has to give, its either the impeller face itself (pitting, breaking vanes), the impeller body, or the bond to the shaft. There are two forces at play here, one is the impact force created by the air pockets and the second is heat which is what the force eventually becomes. Heat isn't the biggest problem of course since this is all embedded in a fluid but it will eventually start to break down the bond between shaft and impeller.

Based on the pictures I wouldn't be so quick to blame just manufacturing for the defect, if it was a manufacturing problem I suspect we would see it more often, then maybe. All manufacturing whether local or offshore is done to a design specification which is all modeled in computers and tested in prototype prior to sending out for manufacturing wherever it is. Manufacturers don't just accept substitute materials, they test them, run them through QA/QC and approve them. Cavitation is real issue and if that is the problem, it probably wasn't in the model design specs, and the impeller is made to a specific design and tolerance with specific materials, bonding agents, etc.. My guess is that design didn't account for cavitation in the system (who would for a closed system). Moving to a steel impeller (or harder material) will just displace the forces to somewhere else in the system, best to make sure there are no air bubbles.

Cavitation typically also manifests itself as noise. It may not be audible over everything else but its not a quiet process (hammering never is). Not sure what to do with that information in this context but there you go.
 
Are we sure its from air leaking into the system ( it’s possible ) but have you listen to the noise the sled makes after you shut it down after a long hard pull… That noise is the cooling of the turbo and does that have anything to do with this issue???
Mine has the gurgle too. Heard it's from the turbo being hot.
 
Are we sure its from air leaking into the system ( it’s possible ) but have you listen to the noise the sled makes after you shut it down after a long hard pull… That noise is the cooling of the turbo and does that have anything to do with this issue???

No. It's designed to do that. Look it up.
 
Mine has the gurgle too. Heard it's from the turbo being hot.

Its by design. That is how the turbo continues to cool despite the engine power being cut. It relies on convection to heat the water creating a temporary pumping effect based purely on the expansion/vacuum cycle created by expansion of the coolant as the turbo heats the nearby water forcing expansion of the water and vacuum feeding into it.
 


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