Step 1: Disassembly
Rotate the driveshaft counterclockwise to unlock the impeller key. Remove the four impeller housing screws.
Slide the water pump off the driveshaft. Remove the impeller key, O-ring, impeller plate, and gasket.
Make sure gasket surface is clean and smooth.
Step 2: Install O-ring in impeller housing groove
ASSEMBLY
Apply a drop of Adhesive 847 in the seal ring groove at each of the four ribs.
Do not allow any adhesive to get into the air bleed groove in the impeller housing. If this groove is blocked by adhesive, the pump will lose its prime and will not pump water.
Install the O-ring in impeller housing groove.
Step 3: Prepare impeller housing
Lightly coat the exterior rim of the impeller cup with Gasket Sealing Compound. Install the cup in the impeller housing. The cup locks in place in the housing with a square index tab.
Make sure vent hole in impeller cup is open.
On outboard models with 1/2 in. diameter water tube, install the water tube grommet with the inside taper facing up.
On outboard models with 5/8 in. diameter water tube, apply a light coat of Triple-Guard grease to the inside of the impeller housing water tube cavity and to the water tube o-rings.
Impeller Housing, P/N 5007968, can be identified by a chamfer on the inside edge of the water tube fitting.
On outboard models with 5/8 in. diameter water tube, remove water tube from exhaust housing and replace o-rings. Apply a light coat of Triple-Guard grease to the o-rings and reinstall water tube in exhaust housing.
Step 4: Install impeller housing cover and grommet
Apply Triple-Guard grease to screw threads and install the impeller housing cover. Tighten screws to a torque of 24 to 36 in. lbs. (3 to 4 Nm).
Apply Adhesive 847 to flat side of the impeller housing grommet. Install the grommet, flat side down.
Step 5: Install impeller into liner
Lightly coat the inside of the liner with Triple-Guard grease. With a counterclockwise rotation, install the impeller into the liner with the slot for the impeller key facing out.
Apply a thin bead of Adhesive 847 in the seal groove, and install the special shaped O-ring seal.
Step 6: Install plate and water pump assembly
Apply Gasket Sealing Compound to both sides of a new impeller plate gasket. Install the gasket and impeller plate.
Apply Triple-Guard grease to a new impeller O-ring. Slide the O-ring down the driveshaft and half way over installed impeller key to temporarily hold key in place.
The sharp edge of the key is the leading edge in clockwise rotation.
Slide the water pump down the driveshaft. Align impeller slot with the impeller key. Rotate the driveshaft to engage the key with the impeller, and slide water pump down over key. Be sure impeller key does not fall out of position.
Make sure the impeller engages the impeller key. Serious powerhead damage will result if impeller key is not in place.
Align the impeller housing with the gearcase. Apply Gasket Sealing Compound to threads of the four impeller housing screws. Tighten the screws to a torque of 60 to 84 in. lbs. (7 to 9.5 Nm).
Step 7: Install water tube sleeve and grommet
On 20 in. outboard models (except 60° V4 and V6), place Grommet, P/N 349354, on housing cover.
On 25 in. and 30 in. outboard models, place the appropriate water tube sleeve and grommet on the impeller housing cover.
Step 8: Prepare to install gearcase
After water pump is assembled completely, rotate driveshaft counter clockwise 1/4 turn to unlock and release impeller and key from driveshaft.
Next, pull up on driveshaft and turn clockwise to lock impeller to shaft. This process increases pump efficiency by locking the impeller in a lower position on the driveshaft.
Before installing gearcase, shift rod adjustment MUST be checked. Refer to appropriate Service Manual.
Install gearcase assembly on outboard. Refer to appropriate Service Manual. Tighten gearcase mounting screws to a torque of:
- 3/8 in. screws – 26 to 28 ft. lbs. (35 to 38 Nm)
- 7/16 in. screws – 45 to 50 ft. lbs. (61 to 68 Nm)
Failure to properly tighten all gearcase retaining screws can result in gearcase loss and loss of boat control at high speed.
Start outboard to check water pump operation.