2010 EC 300 Water pump shaft snapped & bearing collapsed
 

Half way through an Enduro yesterday I crashed whilst flat out up a gnarly hill. The bike fell gently on its right and immediately started rattling/knocking. I presumed it had moved the front pipe but it was not that and something terminal. End of my effort at the Dogs of WOR :(
On inspection I removed the right side engine and found the the water pump shaft snapped and the bearing in the crankcase totally collapsed, even the outer shell of the bearing was hanging out! So not as terminal as thought but still abit of a mess. Should be a reasonably inexpensive and easy fix.
My concern is why or how has this happened as I presume there's minimal load on this drive? Are they prone? Could the bearing of collapsed causing the shaft to snap?...
Any experience shared would be really appreciated :)

This has happened before. Tough to draw conclusion what failed first, but my bet is the shaft. Inspect your impeller, any indication of it contacting the pump cover? Very poor control of tolerance in this area and a plastic part that has failed in the past.

But why this happens when the bike craches to the impeler side ? This is scary...

Cheers Glenn.
Just inspected the cover and yes, it has been rubbing so it may have been just that. I'll get the parts ordered up and see how it looks reassembling.

2010, just a heads up. if any of those bearings got loose, and you need new gears - you will need a complete set. they changed manufacturers in 2011 and the new parts will not fit the old ones. I have a thread out there detailing my 4 month ordeal. GasGas did eventually step up once we figured out what the issue was (they didn't update part numbers). If you just dinged the bearing - go buy a freaking lotto ticket!!!!

Do a search of my threads I've started. I had my engine go because of the pump bearing in the case let go and tanked the bike

Yes, make sure all parts are accounted for. That pump problem is a disgrace. What I did was get a checkpoint alloy impeller, and took about .5 mm off the back so it would clear the cover adequately. Was the plastic impeller melted or distorted? Maybe some extra heat from the hill climb caused it to expand and rub harder, increasing load. Add a weak shaft to the mix and snap!


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Cut a thicker gasket or run two may avoid the issue.

I can see where my plastic impeller has contacted the cover from when the dealer did some work once and just used yamabond instead of a gasket :rolleyes:

I switched it out for a gasket again and kept running the plastic impeller. Will be replacing with a checkpoint during my current rebuild and doing what Glenn did to ensure clearance.

Could you please post some pics of the impeller and the cover ?