How to change the jet pump oil on a Sea-Doo watercraft PWC

Sea-Doo personal watercrafts, often referred to as PWCs or jet skis, are propelled through the water by a jet pump that is a miniature version of an inboard boat engine. The jet pump pulls water in through an inlet hose and ejects the water out a propulsion port at high speed.

Running through thousands of cycles per minutes, jet pumps on Sea-Doo personal watercrafts are potential sources of mechanical problems. To keep the jet pump running smoothly, the oil inside the pump’s casing must be changed regularly.


1) Locate the jet pump at the rear of the Sea-Doo watercraft. If the watercraft is not on a trailer, place the PWC on blocks to raise the rear end enough to enable easy access of the jet pump.

2) Remove the steering cable assembly bolts, which is located at the front of the pump, using a wrench. Pull the cable assembly free from the pump with your hands.

3) Remove the bolts from the trim-arm assembly, which is located at the top of the pump, using a wrench – if so equipped. Not all Sea-Doo models are equipped with a trim system.

4) Remove the bolts on the steering assembly at the rear of the pump with a wrench. Wiggle the assembly free of the pump with your hands. If the assembly does not come free, gently tap around the edges of the assembly with a rubber mallet. Locate and retrieve the rubber O-ring washers located between the pump and the steering assembly.

5) Locate the cone-shaped housing inside the pump. Remove the hex-head plug from the top of the cone with hex-head wrench. Remove the bolts from the perimeter of the cone housing with a wrench.

6) Place a drain pan under the pump and wiggle the front of the cone assembly free from the housing with your hands. Reclaim the O-ring(s) at the ends of the assembly. Elevate the front of the PWC to drain the oil from the jet pump casing.

7) Examine the oil for water, which will be present as pockets of a frothy, light brown creamy substance throughout the oil. If water is present check the bottom of the drain pan for pieces of metal, which indicates the pump needs to be repaired or replaced. If no metal is found in the oil it is a signal the rubber O-rings have failed and require replacement.

8) Spray all internal surfaces of the pump with parts cleaner. Wipe the inside of the pump with a clean, lint-free rag.

9) Consult the See-Doo’s owner’s manual for the recommended grade of jet pump oil. If no manual is available call a dealership or a shop that services Sea-Doos.

10) Wipe the reclaimed O-rings clean with the cloth or install new seals. Apply a light coating of fresh jet pump oil to the O-rings with your fingers. Insert the O-rings into the grooves in the cone housing. Place the cone back on the housing, twisting the cone tightly in place. If the cone will not twist against the housing once it is set in place, then this is is an indication that the O-rings are not seated correctly. Remove the cone and reset the O-rings.

11) Apply thread sealer to the threads of the cone attachment bolts. Reattach the cone to the pump with the bolts and wrench.

12) Fill the pump to the top with fresh oil through the hole at the top of the cone assembly. Apply a drop a thread sealer to the threads of the hex-head plug. Twist the hex-head plug into the fill hole with your fingers and then snug the plug down with a wrench.

13) Coat the O-rings for the steering assembly with oil and set the O-rings in place on the steering assembly. Apply thread sealer to the bolts and reattach the steering, trim-arm and steering cable assemblies to the pump.

Extra tips:

*During disassembly, group loose parts into separate plastic sandwich bags and label the bags with the location of where the parts were removed.

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