Replace the Wear Ring on a Jet Ski
The Wear Ring
The wear ring is exactly what it implies. It's a ring located on the inside of the impeller housing that wears out over time. The more you use your jet ski, the faster the wear ring will wear out.
Before we dive into replacing the wear ring, let's go over some jet ski safety and remind you how the jet ski works.
Safety Tip for New Riders
Your jet ski is essentially a small boat. Boats don't have a brake to stop them. In order to stop, you release the throttle finger pull and the jet ski stops accelerating and eventually comes to a stop. Any object, boat, fellow jet skier, dock, what ever, that is within thirty feet is a potential danger if you don't stop accelerating soon enough.
When approaching an object, direct the jet ski to the side of the object, not directly at it. This way if the jet ski does not come to a stop before the object, it will merely pass by it.
When the accelerator is released, or the jet ski's power is shut off, the ability to turn the jet ski is reduced to zero. The jet engine must have water propelling through it in order to turn.
The first time you take your jet ski on the water, practice. Practicing to maneuver your jet ski, at a slow speed will be a great asset for when there is a loss of power. Most accidents on jet skis happen within the first HOUR of a novice rider entering the water. The concept of no brakes takes a little bit of getting used to, so practice for your own safety as well as others.
How Jet Propulsion Works
A basic understanding of jet propulsion is necessary if you plan on doing your own work. It's different from other powered water vessels (except jet boats) in the manner you turn and stop.
As you can see from the photo above; when the jet ski is running, the impeller draws water up from the surrounding water underneath. The water then passes through the impeller and expelled out the back through the venturi. The nozzle on the end, attached to the venturi, directs the water stream. The nozzle is controlled by the rider via a cable attached to the handlebars and the nozzle. This is the flow of propulsion.
The photo below shows an example using a gallon of water. The venturi narrows the water down super fast and forces it through a smaller hole. Think of a gallon of water, and you put a large straw into it, then force the water as fast as possible out of the gallon through the straw. You can imagine the force the water would come out the straw would be much higher than going into the straw. That's the venturi, the straw, narrowing the water down to increase the force!
When you accelerate the impeller draws water up and through itself, which forces the water out at such a high rate of speed you can turn the handle bars and it will cause the jet ski to move in that direction from the water pushing it. If you decelerate suddenly, or lose power, you loose your ability to steer because you no longer have the forced water to push the jet ski.
Accessing the Wear Ring
Just about anyone with a toolbox can replace a wear ring. A few parts must be removed to access it first. For this hub a 2000 Yamaha XL700Y was the model used. Other jet skis are similar. A manual for your particular model is always helpful. There are some sites that offer the manuals free.
What the Wear Ring Does
If you're asking yourself where does the wear ring come into play, the answer is: every step of the propulsion process.
The wear ring is one of the vital components to the propulsion process of a jet ski. Tucked snugly inside the impellor housing it is often overlooked. If you know what you are looking for you can see it readily. If not, you would be hard pressed to believe there is a vital component that needs replacing.
The wear ring is a liner on the inside of the impellor housing. The impellor grazes along it when it spins. The wear ring...
- Allows the impellor the maximum drawing power to suck up the surrounding water into the jet motor by providing very little dead space.
- Forces the drawn up water to pass through the impeller providing maximum impeller thrust.
- Seals the impeller housing, around the impeller, to provide you, the rider, with maximum speed!
As the jet ski is used the wear ring slowly wears down. Sometimes rocks or fishing weights will be drawn up by the impeller causing dings and scratches in the wear ring. Wearing down or dings in a wear ring will cause a gap to appear between the impeller and the surrounding wear ring. This gap should not exceed 0.10".
When either regular use or foreign objects reduce the capabilites of the wear ring you may notice:
- Reduced turning abilty. Because the wear ring can't seal the impeller in the housing, there is random water sprayed out by the jet, as opposed to directed water.
- Reduced power. The impeller cannot draw the water up and force it through the jet at maximum efficiency causing the jet ski to run slower.
Steps to Accessing the Wear Ring
Put the jet ski on a hoist or table made to hold a jet ski, somewhere you can easily access the back-end where the jet is. Remove these items in the order they are listed.
- ...if equipped, the reverse gate cable and assembly.
- ...6 screws retaining metal plate under the jet pump assembly.
- ...steering cable connection. This is usually sliding sleeve or a nut and screw.
- ...hoses connected to the venturi.
- ...four long screws retaining venturi through pump housing, through impeller housing, to jet ski hull.
- ...venturi. The impeller housing may come out with the venturi and pump housing as one unit. Also, you may need a fiber or rubber hammer to tap on the housing to loosen it for removal. A puller would be even better but not everyone has a jet pump puller, so tap gently.
- If the jet pump housing, and impeller housing, didn't come out in step six, then remove it now.
Now you are ready to get that ring out!
Location of the Wear Ring
Remove the Wear Ring
Reference the thumbnails to remove the wear ring from the impeller housing.
- Locate the wear ring inside the impeller housing.
- Use a saw, dremel or any cutting device that you can control well. When cutting the wear ring it is critical that you do not penetrate the wall of the impeller housing. That kind of damage could be critical in a housing, so be sure your cutting tool is under your control.
- Cut a groove anywhere inside the ring. This is when you will want to pay attention to the depth. The wear ring is about 1/4" thick or less.
- Once you have the groove cut, bend the wear ring down bit by bit all around the edge.
- Slide the ring out of the housing and you're done.
Now let's put the new one in!
Install the Wear Ring
Insert the Wear Ring
Set the wear ring just inside the lip of the impeller housing. Lay a two-by-four across the top. Press down evenly on the two-by-four to get the ring started into the housing. Then use a hammer to tap on the board. Turn the board a quarter turn and tap again. Turning the board every other tap or so. The wear ring is supposed to be very snug. Once it is seated inside the housing you can put everything back as you took it off paying attention to the torque specifications and grease specifications. The impeller may prove to be difficult to slide back into the housing once the new wear ring is in. If it is really difficult; grease the inside of the wear ring to assist the impeller in sliding in.
Wrap it Up
Now that the wear ring is seated inside the impeller housing it's time to put everything back together. Follow the steps for removal in a reverse order. The impeller will be a snug fit when you insert it into the impeller housing due to the new wear ring. Take your time and it will slide in. Make sure you use lock tight on bolts and torque them as specified in your jet ski manual.
Your new wear ring is ready to go. You'll be very happy with the speed and improved handling you'll experience with the new wear ring!