Basic Water Pump Impeller Replacement 
for Johnson and Evinrude outboard motor's

DISCONNECT THE BATTERY PRIOR TO PERFORMING ANY SERVICE OR REPAIRS TO AN OUTBOARD MOTOR
  
  
 

Replacing an outboard impeller does not have to be difficult, and is one of the most important services to perform on an inboard or outboard motor to keep it running proficiently. Impellers should be changed every two or three years regardless of engine use. Impellers will form to the housing and become weak from long periods of non-use.
 

Installation will vary depending on model, make, year, and hp.of your outboard motor, consult a repair manual or seek help from an experienced technicion, and have an exploded view of your lower unit gearcase if possible.

1. Locate where the shift rod connects, and disconnect it.
2. Remove the mounting bolts or hex nuts connecting the lower drive unit to the midsection.
3. Lower the complete unit to the floor making sure it does not turn.
4. If necessary trim the motor upward until the shift rod and driveshaft comes out of the midsection. (use caution when doing this, so the rod and shaft is not wedged and bends).
5. After you remove the drive unit you will need to place it in a stand so the unit is upright and held in place.
6. Remove the rubber seal from the drive shaft if the model has one.
7. Remove the bolts or hex nuts holding the impeller housing.
8. Pull upward on the housing and slide it off the shaft. (if the housing is stuck, use two small pry tools one on each side to loosen the housing, use care not to break the housing using too much force)
9. After the housing is removed (if the impeller did not come off with it remove the impeller)locate the impeller key. 

Installing the new water pump impeller                  
  
1. Make sure you have the right impeller and gaskets or seals.
2. Use some vasilene or light grease and put on drive shaft to hold the impeller key in place.
3. Slide the impeller down the drive shaft making sure the key is in place to lock the impeller.
4. To test it hold the drive shaft and try to turn the impeller, if the impeller turns, repeat no. 3.
5. When you have the impeller and all gaskets or seals in place, apply some lubricant to the inside of the impeller pump housing and slide the housing down the drive shaft to the impeller.
6. While gently applying down pressure on the impeller housing slowly turn the drive shaft clockwise and the housing should slide down over the impeller.
7. Install bolts or hex nuts getting them good and snug, do not overtighten.
8. Reinstall lower drive unit.