Water pump shaft coming off??

(espritv8) · (espritv8) **Join Date: Dec 2009** 07-15-2011, 9:59 PM

I have a mercruiser black scorpion 350. The raw water pump shaft seems out of the housing by half an inch. Of course the belt gets misaligned and comes off the pulley all the time.

Did you ever had a similar problem? What could cause this kind of problem?

(mobv) · (mobv) **Join Date: Jun 2002** 07-16-2011, 5:26 AM

Bearing failure in the pump, time for a new raw water pump.

(wakebrdjay) · (wakebrdjay) **Join Date: Apr 2008** 07-16-2011, 5:58 AM

Yep,had to replace mine beginning of the season.I think it's really important to tighten the bolts to torque specs.(88in.lbs.) when replacing impeller.You can rebuild them,but I couldn't find the parts in stock anywhere so I just replaced whole pump.

(espritv8) · (espritv8) **Join Date: Dec 2009** 07-18-2011, 7:40 AM

ok nice to see i'm not the only one.

i would expect this to fail much later and not at 180 hours. not to impress about reliability...

(wakebrdjay) · (wakebrdjay) **Join Date: Apr 2008** 07-18-2011, 3:33 PM

They're a crappy design and the tension adjusting pulley puts all the tension on the raw water pump pulley.

(espritv8) · (espritv8) **Join Date: Dec 2009** 07-27-2011, 9:45 PM

I tried to get them repaired under warranty. But apparently the item is back order from Mercruiser.

What part number did you order for your black scorpion? 862914t10 or 862914t11? What are those air fittings they are talking about?

(wakebrdjay) · (wakebrdjay) **Join Date: Apr 2008** 07-28-2011, 6:03 AM

862914T10 don't worry about air fittings yours doesn't have them.They are for a drainage system that uses an air pump to drain cooling system.