I applied some grease to the slots for the o rings to help hold them in place.
Yamaha water pump impeller direction.
If this water is not.
But again since you will be looking at the bottom side of the water pump you will be seeing it backwards.
Rotate the drive shaft clockwise and at the same time push down on the pump cover to ease entry of the impeller into the cover.
This needs to be fixed.
Exceptions are pumps with straight vane impellers vanes perpendicular to the shaft and shrouded impellers.
Slide the assembled water pump down over the diveshaft and water pump studs.
If your yamaha 90hp water pump has been neglected for some time it may also be necessary to replace.
Shrouded impellers turn so they scoop the fluid.
Apply thin coat of multipupose lube to inside of the pump cover.
You will turn the driveshaft clockwise for standard right hand rotation models.
Straight vane impellers function in either direction.
While trying to get this on i flipped the impeller.
We recommend you buy the complete yamaha water pump repair kit as it includes the various gaskets o rings and other parts that usually need replacing when you repair the water pump it s much cheaper to buy the complete kit than it is to buy the impeller gaskets and o rings separately.
Install water pump housing turn driveshaft as you place the housing on top of the impeller.
Impellers must turn in a direction so that the fluid is pushed not scooped through the pump see sample drawing below.
As you slide the housing down rotate the driveshaft to align the impeller housing with the pump housing until it slides all the way down over the dowel pins.
Learn from my mistake and check.
Clean the water pump housing.
If you do this correctly the arms of the impeller will curve to the left.
If you did not notice they were all missing or you forgot then remember that all of these motors rotate clockwise.
Be sure the o rings stay in place.
For these reasons it s best to replace your water pump impeller or the entire water pump assembly when servicing these items and never rotate your outboard s crankshaft or driveshaft in a counterclockwise direction.
Re install the water pump housing.
